Properties of Matter. Physical Properties Chemical Properties.
Unit 4 Chemical Properties
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Physical Science Chemical Properties
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Transcript of Unit 4 Chemical Properties
Physical ScienceChemical Properties
Atoms and MoleculesAn Atom is made up of protons, electrons, and neutrons.
An Element is a unique number of protons.
When 2 or more atoms combine together chemically, it is called a molecule.
Molecular Elements
These are allotropes of carbon
Compounds
2 or more elements combined in a molecule
What is a Chemical Reaction?
It is the rearrangement of atoms to form new molecules.
CH4 + 2O2 CO2 + 2H2O
What is a Chemical Reaction?
It is the rearrangement of atoms to form new molecules.
CH4 + 2O2 CO2 + 2H2O
What is a Chemical Reaction?
It is the rearrangement of atoms to form new molecules.
CH4 + 2O2 CO2 + 2H2O
What is a Chemical Reaction?
Some chemical reactions are exothermic
They release energy as heat, light, or other forms.
What is a Chemical Reaction?
Some chemical reactions are endothermic
They absorb energy from the environment to proceed.
Chemical Properties
Chemical properties can only be observed when the substances in a sample of matter are ________________.
_____ and _____ are examples of chemical properties
Chemical Properties
Chemical properties can only be observed when the substances in a sample of matter are ________________. Changing into different substances
_____ and _____ are examples of chemical properties
Chemical Properties
Chemical properties can only be observed when the substances in a sample of matter are ________________. Changing into different substances
_____ and _____ are examples of chemical properties Flammability Reactivity
Triggers to Chemical Reactions
Most reactions do not occur spontaneously.
Most require some trigger to get started.
This could be a spark or even a touch.
Let’s watch a fun video of a chemical reaction that is sensitive to the touch!
Nitrogen Triiodide2 NI3 (s) → N2 (g) + 3 I2 (g),
Nitrogen Triiodide Decomposition
Some Fun Experiments
Mr. Taylor Does Nitrogen Triiodide
http://www.youtube.com/watch?v=hERVtZEZrFQ
Some Fun Experiments
http://www.youtube.com/watch?v=sjLgzgflCk8
THERMITE!
Some Fun Experiments
Pure Metallic Sodium in Water!
http://www.youtube.com/watch?v=gFnNXkcoDSs
Recognizing Chemical Change
Chemical changes are taking place if you see a _____, ______, or ______. Change in color Production of a gas Formation of a precipitate
**If you are watching by recording, send me the sentence above with the answers**
MixturesIron and Sulfur powder in a the mixture
So, it is hypothesis time:
How can we separate the iron from the sulfur?
Enter some ideas in the chat box.
Mixtures
Iron and sulphur – the mixture
How can we separate the iron from the sulphur?
Use a magnet!
Iron is magnetic, sulfur is not...
Turning an iron-sulphur mixture into a Compound
Fe + S FeS Heat
When iron and sulphur react
+sulphur (S) atoms iron (Fe) atoms
When iron and sulphur react
+sulphur (S) atoms iron (Fe) atoms
iron sulphide (FeS) molecules
Differences between compounds and mixtures
MIXTURES COMPOUNDS
1. Mixtures can be separated easily
1. Compounds can not be separated
Differences between compounds and mixtures
MIXTURES COMPOUNDS
1. Mixtures can be separated easily
2. Mixture have the properties of the substances present in it
1. Compounds can not be separated
2. Compounds do not have the properties of the elements
Differences between compounds and mixtures
MIXTURES COMPOUNDS
1. Mixtures can be separated easily
2. Mixture have the properties of the substances present in it
3. No chemical change takes place when a mixture is made
1. Compounds can not be separated
2. Compounds do not have the properties of the elements
3. A compound is always formed due to a chemical reaction
Differences between compounds and mixtures
MIXTURES COMPOUNDS
1. Mixtures can be separated easily
2. Mixture have the properties of the substances present in it
3. No chemical change takes place when a mixture is made
4. There is no heat taken in or given out when a mixture is made
1. Compounds can not be separated
2. Compounds do not have the properties of the elements
3. A compound is always formed due to a chemical reaction
4. Heat is either taken in or given out when a compound is made
Differences between compounds and mixtures
MIXTURES COMPOUNDS
1. Mixtures can be separated easily
2. Mixture have the properties of the substances present in it
3. No chemical change takes place when a mixture is made
4. There is no heat taken in or given out when a mixture is made
5. A mixture can contain elements in any proportion
1. Compounds can not be separated
2. Compounds do not have the properties of the elements
3. A compound is always formed due to a chemical reaction
4. Heat is either taken in or given out when a compound is made
5. A compound always contains the elements in fixed proportions, e.g. FeS contains 7g of iron to 4g of sulphur
