Review: Chemical vs Physical
Review: Vocabulary
Extend: Counting Atoms
Extend: Law of Conservation of Mass
100
Is it a chemical or physical change: pencil breaking

Physical

100

The basic unit of all matter

Atom

100

How many hydrogen atoms: H20

2

100

The law of conservation of mass states that matter can neither be:_______ nor ________

Created nor destroyed 

200

Is it a chemical or physical change: a car rusting

Chemical

200

Two or more atoms bonded together 

Molecule

200

How many hydrogen atoms: 2H2O

4

200

Why must real chemical equations be balanced?

The law of conservation of mass; atoms cannot be created nor destroyed, only transferred

300

Which of the following is NOT a sign of a chemical reaction: a solid forming, a gas forming, a change in state of matter, color changing

A change in state of matter is a physical change (Remember: ice melting does not change its chemical composition)

300
Daily Double! Atoms of different elements chemically combined together in a fixed ratio

Compound

300

What is the total number of atoms in a glucose molecule: C6H12O6

24 (6+12+6= 24)

300

Does the following equation obey the law of the conservation of mass? Explain why it does or does not.
Fe + Cl2 -> FeCl3

No, there is one too many Chlorine on the product side.

400

A beaker is filled with sodium hydroxide and placed on a scale Another liquid- copper sulfate- is inside the beaker but hanging over the liquid in a smaller glass. The copper sulfate is dropped into the sodium hydroxide, forming a solid piece of copper hydroxide in the beaker. What evidence is there that a chemical reaction has occurred? 

Formation of a solid 

400

The small number that shows the number of an atom

Subscript

400

Daily Double: How many atoms of sodium (Na):
2(NaOH)4

8

400

Does the following equation obey the law of the conservation of mass? Explain why it does or does not.
H2 + O2 --> H2O

No, there is one too many oxygen on the reactants side. 

500

A beaker is filled with sodium hydroxide and placed on a scale Another liquid- copper sulfate- is inside the beaker but hanging over the liquid in a smaller glass. The mass on the scale is 60 g. The copper sulfate is dropped into the sodium hydroxide, forming a solid piece of copper hydroxide in the beaker. Will the mass of the beaker increase?

NO, the mass will stay the same. A chemical reaction has occurred, but mass was not created or destroyed. 

500

Which side of the equation shows the reactants and which side shows the products?

Left: Reactants
Right: Products 

500

How many atoms are there for EACH element: 2Ca3(PO4)2

Ca: 6
P: 4
O: 16

500

Hydrogen and Oxygen are diatomic, which means they cannot exist alone. They must always be bonded to another atom. Knowing this, how can you balance the following equation using coefficient(s):
H2 + O2 --> H2O

2H2 + 02 --> 2H20