Chemistry Unit Test Study
Guide
1. The basic unit of matter is:
– An atom
2. List three things that are not made up of
matter and do not have mass:
• light
• sound
• Heat
3. What is the difference between a
chemical change and a physical change?
– A chemical change is when one substance
changes into another substance. The atoms
have been re-arranged, and you can only
change it back if you break the chemical
bonds. Physical changes can be easily
changed back to the original.
4. Give one example of a chemical
change.
– cooking an egg
5. Give one example of a physical
change.
– cutting paper, melting an aluminum can
6. During the chemical reaction of baking
soda and vinegar, bubbles appear.
What’s in the bubbles?
– carbon dioxide
7. What is a reactant?
– a substance that is present at the beginning of a
chemical reaction and is changed into a new
substance.
8. What is a product?
– A substance formed by a chemical reaction.
9.
In a chemical reaction, what are the similarities between
reactants and products?
- the mass of the products and reactants are the same –
the atoms have just been re-arranged.
10. Balance the following equation:
CH4 +
O2
CH4 +
2O2
---------
---------
CO2 +
H 2O
CO2 + 2 H2O
Fe2O3 is the chemical formula for iron oxide (rust).
Answer the following questions using this formula.
11. How many different elements are used to make iron
oxide?
–
2 (Fe and O)
12. How many atoms are needed to make iron oxide?
–
5 (2 Fe and 3 O)
13. How many molecules are represented by this
formula?
–
1
14. What does the Law of Conservation of Matter say?
–
Particles cannot be created or destroyed, only rearranged.
15. What happened when we put steel wool
into a flask and put a balloon over it?
- the balloon was sucked into the flask.
16. What happens to the weight of a glass of
cold lemonade when all of the ice melts?
- the weight stays the same.
17. What are the chemical symbols for the
following elements?
–
–
–
–
–
Hydrogen - H
Oxygen - O
Iron - Fe
Sodium - Na
Copper - Cu
You observe two beakers of water that each have
100 ml of water in them. One contains very hot
water and the other contains very cold water.
18. Which beaker has the greater mass? Why?
- The beaker with the cold water has the greater
mass because the molecules in a cold liquid are
closer together, therefore more can fit in the
beaker.
19. Which beaker has the greater volume, or are
they the same? Why?
- Both beakers have the same volume, 100 ml
20. Which beaker has the greater density? Why?
- The cold beaker has the a greater density
because it has more mass.
21. The Periodic table consists of 18 columns
called ___groups___ and 7 rows called
___periods____.
22. Protons have a __positive___ charge.
Neutrons have a __neutral____ charge. Electrons
have a ___negative__ charge.
23.Most of the elements on the periodic table
are:
– Metals
24. This group of elements got its name because
it almost never reacts with other elements:
– Noble Gases
25. How do you calculate volume?
–
Volume = length * width * height
26. How do you calculate density?
– Density = mass / volume
27. A glass marble has a volume of 5 cm3 and a
mass of 13 g. What is the density of the glass?
– Density of the glass = 13 g / 5 cm3
– Density of the glass = 2.6 g/ cm3