1. Classification of Matter
Chapter 15:
Classification of Matter

2. Matter Matter: anything that has mass and takes up space 4 types:
solid: definite shape & volume
liquid: no definite shape but definite volume
gas: no definite shape or volume
plasma: electrically charged particles

3. Composition of Matter
Atoms: the smallest particle that makes up all matter
Element: substance made up of the same type of atoms all are listed in the periodic table.
Substance: pure matter-either an element or compound

4. Composition of Matter
Compound: two or more elements chemically combined, always in the same ratio; ex. NaCl; H2O
Mixture: a material made up of 2 or more substances that can be separated by physical means. ex. Italian dressing; sand in water; air

5. Types of Mixtures
homogeneous: a mixture where the substances are evenly distributed throughout ex. air; milk, salt water
solution: a homogeneous mixture of particles so small they cannot be seen and will not settle.

6. Types of Mixtures
heterogeneous: a mixture where the materials separate upon standing and keep their individual properties. ex. chocolate milk, trail mix, soda
suspension: a heterogeneous mixture containing a liquid where visible particles settle, ex: Italian dressing

7. Types of Mixtures
Colloid: a mixture with particles that are larger than those in a solution but not heavy enough to settle out. ex: paint; fog; smoke
Tyndall Effect: scattering of light seen in a colloid

8. Matter
Substance
Element
Compound
Mixture
Homogeneous
Heterogeneous

9. Properties of Matter
Physical property: a characteristic of a material that you can observe without changing the identity of the substances that make up the material. ex: appearance; behavior; separation by size, magnetism, filtering, boiling
Physical Change: a change in size, shape, or state of matter- but the identity stays the same. ex. change of state; density; distillation.
density: mass per unit volume of material; m ÷ v
distillation: separating substances by evaporating a liquid and recondensing its vapor.

10. Properties of Matter
Chemical Property: a characteristic of a substance that indicates whether it can undergo a certain chemical change. ex. tendency to burn; oxidize
Chemical Change: a change of one substance into another ex: iron-rust; cooking
Detection of chemical changes:
Foaming ✓ Bubbling
Heat ✓ Light
Sound

11. Weathering Weathering: the wearing away of Earth’s surface
Chemical change: calcium carbonate + acidic rain
Physical change: cracking of rocks; streams wearing away rock  canyons

12. Law of Conservation of Mass: the mass of all substances that are present before a chemical change = the mass of all the substances that remain after the change.
Chemical Reactions: when one or more substances changes into a new and different substance.

13. Writing a Chemical Equation Uses
Chemical formulas- shows elements; # atoms/molecules
Reactants: substances that combine/change
Products: the new substances that are formed
Symbols- shows state of reactants/products (solid (s), aqueous (aq); gas (g); precipitate (p)
Subscripts- numbers that tell # atoms of each element present
Coefficients- numbers that tell # molecules of each substance present.

14. Chemical Equation for Photosynthesis
Long hand method of describing
6 molecules of carbon dioxide added to 6 molecules of water in the presence of light and chlorophyll yields 6 molecules of glucose and 6 molecules of oxygen
Chemical Formula for describing photosynthesis: short method
6CO2 (g) +6H2O (aq)  C6H12O6 (aq) + 6O2 (g)
Sunlight & Chlorophyll

15. The law of conservation of mass states that matter cannot be created or destroyed, THEREFORE, all chemical equations must be balanced when written. BOTH SIDES OF AN EQUATION MUST HAVE THE SAME NUMBER OF ATOMS OF EACH ELEMENT OR THE EQUATION IS NOT WRITTREN CORRECTLY OR BALANCED.
To balance an equation you must choose only the coefficients that will help you get the same number of atoms on each side of the equation

16. Steps to Balance an Equation:
Identify the names of elements present in the reaction.
Draw a wall in between the reactants and products.
Under each element write the number of each present.
Add coefficients where needed for balance.

17. Try on your own to balance:
__ C6H12O6 + __ CO2  __ H2O + __ CO2 + energy
_____ H2 + _____ O2  _____ H2O
_____ N2 +_____ H2  ______ NH3
_____ Fe + _____ O2  _____ Fe2O3