Determine the number of protons, neutrons and electrons for the following elements:
S
Cu
Fe
Wednesday, September 29, 2010
Color Code the Periodic Table
Color Coding the Periodic Table
Student Information Sheet
The Periodic Table is a list of all the known elements. It is organized by increasing atomic number. There are two main groups on the periodic table: metals and nonmetals. The left side of the table contains elements with the greatest metallic properties. As you move from the left to the right, the elements become less metallic with the far right side of the table consisting of nonmetals. The elements in the middle of the table are called “transition” elements because they are changed from metallic properties to nonmetallic properties. A small group whose members touch the zigzag line are called metalloids because they have both metallic and nonmetallic properties.
The table is also arranged in vertical columns called “groups” or “families” and horizontal rows called “periods.” Each arrangement is significant. The elements in each vertical column or group have similar properties. Group 1 elements all have the electron in their outer shells. This gives them similar properties. Group 2 elements all have 2 electrons in their outer shells. This also gives them similar properties. Not all of the groups, however, hold true for this pattern. The elements in the first period or row all have one shell. The elements in period 2 all have 2 shells. The elements in period 3 have 3 shells and so on.
There are a number of major groups with similar properties. They are as follows:
Hydrogen: This element does not match the properties of any other group so it stands alone. It is placed above group 1 but it is not part of that group. It is a very reactive, colorless, odorless gas at room temperature. (1 outer level electron)
Group 1: Alkali Metals – These metals are extremely reactive and are never found in nature in their pure form. They are silver colored and shiny. Their density is extremely low so that they are soft enough to be cut with a knife. (1 outer level electron)
Group 2: Alkaline-earth Metals – Slightly less reactive than alkali metals. They are silver colored and more dense than alkali metals. (2 outer level electrons)
Groups 3 – 12: Transition Metals – These metals have a moderate range of reactivity and a wide range of properties. In general, they are shiny and good conductors of heat and electricity. They also have higher densities and melting points than groups 1 & 2. (1 or 2 outer level electrons)
Lanthanides and Actinides: These are also transition metals that were taken out and placed at the bottom of the table so the table wouldn’t be so wide. The elements in each of these two periods share many properties. The lanthanides are shiny and reactive. The actinides are all radioactive and are therefore unstable. Elements 95 through 103 do not exist in nature but have been manufactured in the lab.
Group 13: Boron Group – Contains one metalloid and 4 metals. Reactive. Aluminum is in this group. It is also the most abundant metal in the earth’s crust. (3 outer level electrons)
Group 14: Carbon Group – Contains on nonmetal, two metalloids, and two metals. Varied reactivity. (4 outer level electrons)
Group 15: Nitrogen Group – Contains two nonmetals, two metalloids, and one metal. Varied reactivity. (5 outer level electrons)
Group 16: Oxygen Group – Contains three nonmetals, one metalloid, and one metal. Reactive group. (6 outer level electrons)
Groups 17: Halogens – All nonmetals. Very reactive. Poor conductors of heat and electricity. Tend to form salts with metals. Ex. NaCl: sodium chloride also known as “table salt”. (7 outer level electrons)
Groups 18: Noble Gases – Unreactive nonmetals. All are colorless, odorless gases at room temperature. All found in earth’s atmosphere in small amounts. (8 outer level electrons)
Color Coding the Periodic Table
Student Worksheet
This worksheet will help you understand how the periodic table is arranged. Your teacher will give you a copy of the periodic table to color. Using map pencils, color each group on the table as follows:
1. Color the square for Hydrogen pink.
2. Lightly color all metals yellow.
3. Place black dots in the squares of all alkali metals.
4. Draw a horizontal line across each box in the group of alkaline earth metals.
5. Draw a diagonal line across each box of all transition metals.
6. Color the metalloids purple.
7. Color the nonmetals orange.
8. Draw small brown circles in each box of the halogens.
9. Draw checkerboard lines through all the boxes of the noble gases.
10. Using a black color, trace the zigzag line that separates the metals from the nonmetals.
11. Color all the lanthanides red.
12. Color all the actinides green.
When you are finished, make a key that indicates which color identifies which group.
Student Information Sheet
The Periodic Table is a list of all the known elements. It is organized by increasing atomic number. There are two main groups on the periodic table: metals and nonmetals. The left side of the table contains elements with the greatest metallic properties. As you move from the left to the right, the elements become less metallic with the far right side of the table consisting of nonmetals. The elements in the middle of the table are called “transition” elements because they are changed from metallic properties to nonmetallic properties. A small group whose members touch the zigzag line are called metalloids because they have both metallic and nonmetallic properties.
The table is also arranged in vertical columns called “groups” or “families” and horizontal rows called “periods.” Each arrangement is significant. The elements in each vertical column or group have similar properties. Group 1 elements all have the electron in their outer shells. This gives them similar properties. Group 2 elements all have 2 electrons in their outer shells. This also gives them similar properties. Not all of the groups, however, hold true for this pattern. The elements in the first period or row all have one shell. The elements in period 2 all have 2 shells. The elements in period 3 have 3 shells and so on.
There are a number of major groups with similar properties. They are as follows:
Hydrogen: This element does not match the properties of any other group so it stands alone. It is placed above group 1 but it is not part of that group. It is a very reactive, colorless, odorless gas at room temperature. (1 outer level electron)
Group 1: Alkali Metals – These metals are extremely reactive and are never found in nature in their pure form. They are silver colored and shiny. Their density is extremely low so that they are soft enough to be cut with a knife. (1 outer level electron)
Group 2: Alkaline-earth Metals – Slightly less reactive than alkali metals. They are silver colored and more dense than alkali metals. (2 outer level electrons)
Groups 3 – 12: Transition Metals – These metals have a moderate range of reactivity and a wide range of properties. In general, they are shiny and good conductors of heat and electricity. They also have higher densities and melting points than groups 1 & 2. (1 or 2 outer level electrons)
Lanthanides and Actinides: These are also transition metals that were taken out and placed at the bottom of the table so the table wouldn’t be so wide. The elements in each of these two periods share many properties. The lanthanides are shiny and reactive. The actinides are all radioactive and are therefore unstable. Elements 95 through 103 do not exist in nature but have been manufactured in the lab.
Group 13: Boron Group – Contains one metalloid and 4 metals. Reactive. Aluminum is in this group. It is also the most abundant metal in the earth’s crust. (3 outer level electrons)
Group 14: Carbon Group – Contains on nonmetal, two metalloids, and two metals. Varied reactivity. (4 outer level electrons)
Group 15: Nitrogen Group – Contains two nonmetals, two metalloids, and one metal. Varied reactivity. (5 outer level electrons)
Group 16: Oxygen Group – Contains three nonmetals, one metalloid, and one metal. Reactive group. (6 outer level electrons)
Groups 17: Halogens – All nonmetals. Very reactive. Poor conductors of heat and electricity. Tend to form salts with metals. Ex. NaCl: sodium chloride also known as “table salt”. (7 outer level electrons)
Groups 18: Noble Gases – Unreactive nonmetals. All are colorless, odorless gases at room temperature. All found in earth’s atmosphere in small amounts. (8 outer level electrons)
Color Coding the Periodic Table
Student Worksheet
This worksheet will help you understand how the periodic table is arranged. Your teacher will give you a copy of the periodic table to color. Using map pencils, color each group on the table as follows:
1. Color the square for Hydrogen pink.
2. Lightly color all metals yellow.
3. Place black dots in the squares of all alkali metals.
4. Draw a horizontal line across each box in the group of alkaline earth metals.
5. Draw a diagonal line across each box of all transition metals.
6. Color the metalloids purple.
7. Color the nonmetals orange.
8. Draw small brown circles in each box of the halogens.
9. Draw checkerboard lines through all the boxes of the noble gases.
10. Using a black color, trace the zigzag line that separates the metals from the nonmetals.
11. Color all the lanthanides red.
12. Color all the actinides green.
When you are finished, make a key that indicates which color identifies which group.
Dalton's Atomic Theory
Dalton's Atomic Theory
1) All matter is made of atoms. Atoms are indivisible and indestructible.
2) All atoms of a given element are identical in mass and properties
3) Compounds are formed by a combination of two or more different kinds of atoms.
4) A chemical reaction is a rearrangement of atoms
1) All matter is made of atoms. Atoms are indivisible and indestructible.
2) All atoms of a given element are identical in mass and properties
3) Compounds are formed by a combination of two or more different kinds of atoms.
4) A chemical reaction is a rearrangement of atoms
Periodic Table Vocabulary
alkali metals
group
nonmetal
alkaline earth metal
halogen
nucleus
atom
inner transition metal
period
atomic mass
isotope
periodic law
atomic mass unit (amu)
mass number
periodic table
atomic number
metal
proton
cathode ray
metalloid
representative element
Dalton’s atomic theory
neutron
transition metal
electron
noble gas
group
nonmetal
alkaline earth metal
halogen
nucleus
atom
inner transition metal
period
atomic mass
isotope
periodic law
atomic mass unit (amu)
mass number
periodic table
atomic number
metal
proton
cathode ray
metalloid
representative element
Dalton’s atomic theory
neutron
transition metal
electron
noble gas
Introduction to the Periodic Table Vocabulary
History
Mendeleev
Organization
Periods, Groups, Families
Trends
Atomic Radii
Ionization
Electricity
Mendeleev
Organization
Periods, Groups, Families
Trends
Atomic Radii
Ionization
Electricity
Sunday, September 26, 2010
Lab Journal Check
You must have the following in your journal as September 25, 2010
Lab 1 Advertisement
Lab 2 Milk
Lab 3 Sugar Dissolving Rates
Lab 4 Separation of Mixtures
Bellringer 1-9
Lab 1 Advertisement
Lab 2 Milk
Lab 3 Sugar Dissolving Rates
Lab 4 Separation of Mixtures
Bellringer 1-9
TAKS April 2009 Benchmark
http://ritter.tea.state.tx.us/student.assessment/resources/release/tests2009/taks_g10_science.pdf
Monday, September 20, 2010
Atomic Math Games, Periodic Table and Videos
Link to the following for a copy of the periodic table:
http://www.nysedregents.org/testing/reftable/archreftable/chempertable.pdf
For Atomic Math Calculations Game, go to
http://education.jlab.org/elementmath/index.html
For a video to explain atomic number and mass, go to
http://www.nysedregents.org/testing/reftable/archreftable/chempertable.pdf
http://www.nysedregents.org/testing/reftable/archreftable/chempertable.pdf
For Atomic Math Calculations Game, go to
http://education.jlab.org/elementmath/index.html
For a video to explain atomic number and mass, go to
http://www.nysedregents.org/testing/reftable/archreftable/chempertable.pdf
Sunday, September 19, 2010
Bellringer Week 2
1. The smallest particle of matter is a ____ .
a. atom
b. electron
c. proton
d. quark
2. Physical changes are indicated by
a. change of substance
b. rearranging the atoms
c. new products formed
d. new atoms formed
a. atom
b. electron
c. proton
d. quark
2. Physical changes are indicated by
a. change of substance
b. rearranging the atoms
c. new products formed
d. new atoms formed
Separation Techniques
Distillation
METHODS of SEPARATING MIXTURES and purifying substances
Simple Distillation
Distillation involves 2 stages and both are physical state changes.
(1) The liquid or solution mixture is boiled to vaporise the most volatile component in the mixture (liquid ==> gas). The ant-bumping granules give a smoother boiling action.
(2) The vapour is cooled by cold water in the condenser to condense (gas ==> liquid) it back to a liquid (the distillate) which is collected.
This can be used to purify water because the dissolved solids have a much higher boiling point and will not evaporate with the steam, BUT it is too simple a method to separate a mixture of liquids especially if the boiling points are relatively close.
Fractional Distillation
Fractional Distillation
Fractional distillation involves 2 main stages and both are physical state changes. It can only work with liquids with different boiling points. However, this method only works if all the liquids in the mixture are miscible (e.g. alcohol/water, crude oil etc.) and do NOT separate out into layers like oil/water.
(1) The liquid or solution mixture is boiled to vaporise the most volatile component in the mixture (liquid ==>gas). The ant-bumping granules give a smoother boiling action.
(2) The vapour passes up through a fractionating column, where the separation takes place (theory at the end). This column is not used in the simple distillation described above.
(3) The vapour is cooled by cold water in the condenser to condense (gas ==> liquid) it back to a liquid (the distillate) which is collected.
This can be used to separate alcohol from a fermented sugar solution.
It is used on a large scale to separate the components of crude oil, because the different hydrocarbons have different boiling and condensation points (see oil).
FRACTIONAL DISTILLATION THEORY:
Imagine green liquid is a mixture of a blue liquid (boiling point 80oC) and a yellow liquid (boiling point 100oC), so we have a coloured diagram simulation of a colourless alcohol and water mixture! As the vapour from the boiling mixture enters the fractionating column it begins to cool and condense. The highest boiling or least volatile liquid tends to condense more i.e. the yellow liquid (water). The lower boiling more volatile blue liquid gets further up the column. Gradually up the column the blue and yellow separate from each other so that yellow condenses back into the flask and pure blue distils over to be collected. The 1st liquid, the lowest boiling point, is called the 1st fraction and each liquid distils over when the top of the column reaches its particular boiling point to give the 2nd, 3rd fraction etc.
To increase the separation efficiency of the tall fractionating column, it is usually packed with glass beads, short glass tubes or glass rings etc. which greatly increase the surface area for evaporation and condensation.
In the distillation of crude oil the different fractions are condensed out at different points in a huge fractionating column. At the top are the very low boiling fuel gases like butane and at the bottom are the high boiling big molecules of waxes and tar.
Chromatography
Paper or Thin Layer Chromatography
This method of separation is used to see what coloured materials make up e.g. a food dye analysis.
The material to be separated e.g. a food dye (6) is dissolved in a solvent and carefully spotted onto chromatography paper or a thin layer of a white mineral material on a glass sheet. Alongside it are spotted known colours on a 'start line' (1-5).
The paper is carefully dipped into a solvent, which is absorbed into the paper and rises up it. The solvent may be water or an organic liquid like an alcohol (e.g. ethanol) or a hydrocarbon, so-called non-aqueous solvents. For accurate work the distance moved by the solent is marked on carefully with a pencil and the distances moved by each 'centre' of the coloured spots is also measured. These can be compared with known substances BUT if so, the identical paper and solvent must be used (See Rf values below).
Due to different solubilities and different molecular 'adhesion' some colours move more than others up the paper, so effecting the separation of the different coloured molecules.
Any colour which horizontally matches another is likely to be the same molecule i.e. red (1 and 6), brown (3 and 6) and blue (4 and 6) match, showing these three are all in the food dye (6).
The distance a substance moves, compared to the distance the solvent front moves (top of grey area on 2nd diagram) is called the reference or Rf valueand has a value of 0.0 (not moved - no good), to 1.0 (too soluble - no good either), but Rf ratio values between 0.1 and 0.9 can be useful for analysis and identification.
Rf = distance moved by dissolved substance (solute) / distance moved by solvent.
Some technical terms: The substances (solutes) to be analysed must dissolve in the solvent, which is called the mobile phase because it moves. The paper or thin layer of material on which the separation takes place is called the stationary or immobile phase because it doesn't move.
It is possible to analyse colourless mixture if the components can be made coloured e.g. protein can be broken down into amino acids and coloured purple by a chemical reagent called Ninhydrin and many colourless organic molecules fluoresce when ultra-violet light is shone on them. These are called locating agents.
Thin layer chromatograpy (t.l.c) is where a layer of paste is thinly and evenly spread on e.g. a glass plate. The paste consists of the solid immobile phase like aluminium oxide dispersesd in a liquid such as water. The plate is allowed to dry and then used in the same way as paper chromatography.
Crystallization
Filtration
Go to this link to view seperation diagrams:
http://www.gcsescience.com/e4-mixture-separation.htm
Posted by Hao Tran at 8:09 PM 0 comments
METHODS of SEPARATING MIXTURES and purifying substances
Simple Distillation
Distillation involves 2 stages and both are physical state changes.
(1) The liquid or solution mixture is boiled to vaporise the most volatile component in the mixture (liquid ==> gas). The ant-bumping granules give a smoother boiling action.
(2) The vapour is cooled by cold water in the condenser to condense (gas ==> liquid) it back to a liquid (the distillate) which is collected.
This can be used to purify water because the dissolved solids have a much higher boiling point and will not evaporate with the steam, BUT it is too simple a method to separate a mixture of liquids especially if the boiling points are relatively close.
Fractional Distillation
Fractional Distillation
Fractional distillation involves 2 main stages and both are physical state changes. It can only work with liquids with different boiling points. However, this method only works if all the liquids in the mixture are miscible (e.g. alcohol/water, crude oil etc.) and do NOT separate out into layers like oil/water.
(1) The liquid or solution mixture is boiled to vaporise the most volatile component in the mixture (liquid ==>gas). The ant-bumping granules give a smoother boiling action.
(2) The vapour passes up through a fractionating column, where the separation takes place (theory at the end). This column is not used in the simple distillation described above.
(3) The vapour is cooled by cold water in the condenser to condense (gas ==> liquid) it back to a liquid (the distillate) which is collected.
This can be used to separate alcohol from a fermented sugar solution.
It is used on a large scale to separate the components of crude oil, because the different hydrocarbons have different boiling and condensation points (see oil).
FRACTIONAL DISTILLATION THEORY:
Imagine green liquid is a mixture of a blue liquid (boiling point 80oC) and a yellow liquid (boiling point 100oC), so we have a coloured diagram simulation of a colourless alcohol and water mixture! As the vapour from the boiling mixture enters the fractionating column it begins to cool and condense. The highest boiling or least volatile liquid tends to condense more i.e. the yellow liquid (water). The lower boiling more volatile blue liquid gets further up the column. Gradually up the column the blue and yellow separate from each other so that yellow condenses back into the flask and pure blue distils over to be collected. The 1st liquid, the lowest boiling point, is called the 1st fraction and each liquid distils over when the top of the column reaches its particular boiling point to give the 2nd, 3rd fraction etc.
To increase the separation efficiency of the tall fractionating column, it is usually packed with glass beads, short glass tubes or glass rings etc. which greatly increase the surface area for evaporation and condensation.
In the distillation of crude oil the different fractions are condensed out at different points in a huge fractionating column. At the top are the very low boiling fuel gases like butane and at the bottom are the high boiling big molecules of waxes and tar.
Chromatography
Paper or Thin Layer Chromatography
This method of separation is used to see what coloured materials make up e.g. a food dye analysis.
The material to be separated e.g. a food dye (6) is dissolved in a solvent and carefully spotted onto chromatography paper or a thin layer of a white mineral material on a glass sheet. Alongside it are spotted known colours on a 'start line' (1-5).
The paper is carefully dipped into a solvent, which is absorbed into the paper and rises up it. The solvent may be water or an organic liquid like an alcohol (e.g. ethanol) or a hydrocarbon, so-called non-aqueous solvents. For accurate work the distance moved by the solent is marked on carefully with a pencil and the distances moved by each 'centre' of the coloured spots is also measured. These can be compared with known substances BUT if so, the identical paper and solvent must be used (See Rf values below).
Due to different solubilities and different molecular 'adhesion' some colours move more than others up the paper, so effecting the separation of the different coloured molecules.
Any colour which horizontally matches another is likely to be the same molecule i.e. red (1 and 6), brown (3 and 6) and blue (4 and 6) match, showing these three are all in the food dye (6).
The distance a substance moves, compared to the distance the solvent front moves (top of grey area on 2nd diagram) is called the reference or Rf valueand has a value of 0.0 (not moved - no good), to 1.0 (too soluble - no good either), but Rf ratio values between 0.1 and 0.9 can be useful for analysis and identification.
Rf = distance moved by dissolved substance (solute) / distance moved by solvent.
Some technical terms: The substances (solutes) to be analysed must dissolve in the solvent, which is called the mobile phase because it moves. The paper or thin layer of material on which the separation takes place is called the stationary or immobile phase because it doesn't move.
It is possible to analyse colourless mixture if the components can be made coloured e.g. protein can be broken down into amino acids and coloured purple by a chemical reagent called Ninhydrin and many colourless organic molecules fluoresce when ultra-violet light is shone on them. These are called locating agents.
Thin layer chromatograpy (t.l.c) is where a layer of paste is thinly and evenly spread on e.g. a glass plate. The paste consists of the solid immobile phase like aluminium oxide dispersesd in a liquid such as water. The plate is allowed to dry and then used in the same way as paper chromatography.
Crystallization
Filtration
Go to this link to view seperation diagrams:
http://www.gcsescience.com/e4-mixture-separation.htm
Posted by Hao Tran at 8:09 PM 0 comments
Compounds, Mixtures, Elements and Separation Methods
Here's a good resource for definitions of
compounds, mixtures, elements and seperation methods
http://www.docbrown.info/page01/ElCpdMix/EleCmdMix.htm#Introduction
compounds, mixtures, elements and seperation methods
http://www.docbrown.info/page01/ElCpdMix/EleCmdMix.htm#Introduction
Seperation of Mixtures Quiz
Go to this link, answer the quiz and print your results.
http://www.gcsescience.com/q/qelcomsep.html
http://www.gcsescience.com/q/qelcomsep.html
Wednesday, September 15, 2010
Mixtures Vocabulary
Chromatography
Concentrated
Magnet
Evaporation
Solvent
Solute
Dissolve
Solution
Crystalline
Amorphous
Suspension
Insoluble
Dilute
Saturated
Mixture
Filtration
Concentrated
Magnet
Evaporation
Solvent
Solute
Dissolve
Solution
Crystalline
Amorphous
Suspension
Insoluble
Dilute
Saturated
Mixture
Filtration
Thursday, September 9, 2010
Seperation of Mixtures
Evaporation
Filtration
Paper Chromatography
Distillation
Centrifuge
Seperating funnel
Magnet
Decanting
Filtration
Paper Chromatography
Distillation
Centrifuge
Seperating funnel
Magnet
Decanting
Lab 3: Case of the Disappearing Sugar Cube
STANDARD Students will observe and describe chemical and physical change.
OBJECTIVE
Differentiate between common chemical and physical changes.
Analyze factors that influence chemical and physical change.
INTENDED LEARNING OUTCOMES
1a. Make observations and measurements
2d. Collect and record data using procedures designed to minimize error.
2e. Analyze data and draw warranted inferences.
Introduction
To help teach students how stirring, temperature, concentration, surface area and crushing affect reaction rates. This is an open ended activity which can also be used to assess students understanding of the affects of variables on reaction rates. Students should work in groups of at least two.
Materials
1 sugar cube per group
stirring rods
mortar and pestle or something to crush the cubes
50 or 100 ml beakers
Hot plate and pot to boil water with a ladle
graduated cylinders
stop watches
Procedure
1. Place 1 sugar cube in a 50 or 100 ml beaker with 40 ml of cold water and time how long it takes to dissolve and record the time. Have students use the classroom clock to time this one.
2. Place 1 sugar cube crushed in a 50 or 100 ml beaker with 40 ml of cold water, time how long it takes to dissolve and record the time.
3. Place 1 sugar cube crushed in a 50 or 100 ml beaker with 40 ml of cold water and stir it until it dissolves. Time how long it takes to dissolve and record the time.
4. Place 1 sugar cube crushed in a 50 or 100 ml beaker with 40 ml of hot water and stir it until it dissolves. Time how long it takes to dissolve and record the time.
Analysis
Begin discussion by asking students what things were the same in the four procedures? What things did we change? What affect did these changes have on the time it took the sugar to dissolve? What is a variable? Define for students what a variable is and then have them come up with a procedure that will dissolve the sugar cube the fastest and then have them test their hypothesis by racing against the rest of the students in the class.
Variation
If you have the time you can have the students do first solid cube cold water and then solid cube hot water. Then have the students do a crushed cube in cold and hot water. Finally have them do a crushed cube with stirring in cold and hot water.
OBJECTIVE
Differentiate between common chemical and physical changes.
Analyze factors that influence chemical and physical change.
INTENDED LEARNING OUTCOMES
1a. Make observations and measurements
2d. Collect and record data using procedures designed to minimize error.
2e. Analyze data and draw warranted inferences.
Introduction
To help teach students how stirring, temperature, concentration, surface area and crushing affect reaction rates. This is an open ended activity which can also be used to assess students understanding of the affects of variables on reaction rates. Students should work in groups of at least two.
Materials
1 sugar cube per group
stirring rods
mortar and pestle or something to crush the cubes
50 or 100 ml beakers
Hot plate and pot to boil water with a ladle
graduated cylinders
stop watches
Procedure
1. Place 1 sugar cube in a 50 or 100 ml beaker with 40 ml of cold water and time how long it takes to dissolve and record the time. Have students use the classroom clock to time this one.
2. Place 1 sugar cube crushed in a 50 or 100 ml beaker with 40 ml of cold water, time how long it takes to dissolve and record the time.
3. Place 1 sugar cube crushed in a 50 or 100 ml beaker with 40 ml of cold water and stir it until it dissolves. Time how long it takes to dissolve and record the time.
4. Place 1 sugar cube crushed in a 50 or 100 ml beaker with 40 ml of hot water and stir it until it dissolves. Time how long it takes to dissolve and record the time.
Analysis
Begin discussion by asking students what things were the same in the four procedures? What things did we change? What affect did these changes have on the time it took the sugar to dissolve? What is a variable? Define for students what a variable is and then have them come up with a procedure that will dissolve the sugar cube the fastest and then have them test their hypothesis by racing against the rest of the students in the class.
Variation
If you have the time you can have the students do first solid cube cold water and then solid cube hot water. Then have the students do a crushed cube in cold and hot water. Finally have them do a crushed cube with stirring in cold and hot water.
Monday, September 6, 2010
Physical and Chemical Properties Powerpoint
http://www.dentonisd.org/52720812134413/lib/52720812134413/_files/Physical_Chemical_Properties.pdf
Physical and Chemical Properties/States of Matter
The properties of a substance are those characteristics that are used to identify or describe it. When we say that water is "wet", or that silver is "shiny", we are describing materials in terms of their properties. Properties can be divided into the categories of physical properties and chemical properties. Physical properties are readily observable, like; color, size, luster, or smell. Chemical properties are only observable during a chemical reaction. For example, you might not know if sulfur is combustible unless you tried to burn it.
Another way of separating kinds of properties is to think about whether or not the size of a sample would affect a particular property. No matter how much pure copper you have, it always has the same distinctive color. No matter how much water you have, it always freezes at zero degrees Celsius under standard atmospheric conditions. Methane gas is combustible, no matter the size of the sample. Properties, which do not depend on the size of the sample involved, like those described above, are called intensive properties. Some of the most common intensive properties are; density, freezing point, color, melting point, reactivity, luster, malleability, and conductivity.
Extensive properties are those that do depend on the size of the sample involved. A large sample of carbon would take up a bigger area than a small sample of carbon, so volume is an extensive property. Some of the most common types of extensive properties are; length, volume, mass and weight.
Pieces of matter undergo various changes all of the time. Some changes, like an increase in temperature, are relatively minor. Other changes, like the combustion of a piece of wood, are fairly drastic. These changes are divided into the categories of Physical and Chemical change. The main factor that distinguishes one category form the other is whether or not a particular change results in the production of a new substance.
Physical changes are those changes that do not result in the production of a new substance. If you melt a block of ice, you still have H2O at the end of the change. If you break a bottle, you still have glass. Painting a piece of wood will not make it stop being wood. Some common examples of physical changes are; melting, freezing, condensing, breaking, crushing, cutting, and bending. Special types of physical changes where any object changes state, such as when water freezes or evaporates, are sometimes called change of state operations.
Chemical changes, or chemical reactions, are changes that result in the production of another substance. When you burn a log in a fireplace, you are carrying out a chemical reaction that releases carbon. When you light your Bunsen burner in lab, you are carrying out a chemical reaction that produces water and carbon dioxide. Common examples of chemical changes that you may be somewhat familiar with are; digestion, respiration, photosynthesis, burning, and decomposition.
http://www.fordhamprep.org/gcurran/sho/sho/lessons/lesson15.htm
Another way of separating kinds of properties is to think about whether or not the size of a sample would affect a particular property. No matter how much pure copper you have, it always has the same distinctive color. No matter how much water you have, it always freezes at zero degrees Celsius under standard atmospheric conditions. Methane gas is combustible, no matter the size of the sample. Properties, which do not depend on the size of the sample involved, like those described above, are called intensive properties. Some of the most common intensive properties are; density, freezing point, color, melting point, reactivity, luster, malleability, and conductivity.
Extensive properties are those that do depend on the size of the sample involved. A large sample of carbon would take up a bigger area than a small sample of carbon, so volume is an extensive property. Some of the most common types of extensive properties are; length, volume, mass and weight.
Pieces of matter undergo various changes all of the time. Some changes, like an increase in temperature, are relatively minor. Other changes, like the combustion of a piece of wood, are fairly drastic. These changes are divided into the categories of Physical and Chemical change. The main factor that distinguishes one category form the other is whether or not a particular change results in the production of a new substance.
Physical changes are those changes that do not result in the production of a new substance. If you melt a block of ice, you still have H2O at the end of the change. If you break a bottle, you still have glass. Painting a piece of wood will not make it stop being wood. Some common examples of physical changes are; melting, freezing, condensing, breaking, crushing, cutting, and bending. Special types of physical changes where any object changes state, such as when water freezes or evaporates, are sometimes called change of state operations.
Chemical changes, or chemical reactions, are changes that result in the production of another substance. When you burn a log in a fireplace, you are carrying out a chemical reaction that releases carbon. When you light your Bunsen burner in lab, you are carrying out a chemical reaction that produces water and carbon dioxide. Common examples of chemical changes that you may be somewhat familiar with are; digestion, respiration, photosynthesis, burning, and decomposition.
http://www.fordhamprep.org/gcurran/sho/sho/lessons/lesson15.htm
Thursday, September 2, 2010
More Vocabulary
Chapter 1
analytical chemistry
hypothesis
physical chemistry
biochemistry
inorganic chemistry
scientific law
chemistry
observation
scientific method
experiment
organic chemistry
theory
Chapter 2
chemical property
homogeneous mixture
physical change
chemical reaction
law of conservation of mass
physical property
chemical symbol
liquid
product
compound
mass
reactant
distillation
matter
solid
element
mixture
solution
gas
phase
substance
heterogeneous mixture
vapor
analytical chemistry
hypothesis
physical chemistry
biochemistry
inorganic chemistry
scientific law
chemistry
observation
scientific method
experiment
organic chemistry
theory
Chapter 2
chemical property
homogeneous mixture
physical change
chemical reaction
law of conservation of mass
physical property
chemical symbol
liquid
product
compound
mass
reactant
distillation
matter
solid
element
mixture
solution
gas
phase
substance
heterogeneous mixture
vapor
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