1. MATTER AND ENERGY REVIEW
1. Define matter and explain how to measure it. Define and explain the concept of
density.
2. Explain the atom structure and what an ion is.
3. Fill up the table below.
Atom Mass Protons Neutrons Electrons
Carbon 12 6
Chlorine 17 18
Oxygen 8
Nitrogen 14 7
Lead 207 82
4. Use the scientific notation to express the following numbers as powers of ten:
a. 1 000 000
b. 2 000 000
c. 0.000 000 000 000 1
d. 0.000 245
e. 56 000 000 000 000
f. 0.000 000 234 671
5. Write the numbers that correspond to the following numbers in scientific notation:
a. 5.89 x 10-5
b. 5 x 107
c. 35 x 10-12
d. 2.234 x 108
6. Name and define the different ways atoms have to organize in matter.
7. Define: molecule, ionic bond, simple substance, compound.
8. What is a formula? Explain giving an example.

2. MATTER AND ENERGY
9. Explain the concept of energy and work and give examples.
10. What do we need for a transformation to occur? What are the different
transformations that matter can undergo?
11. Name and define the different types of systems.
12. Explain the energy changes in the next examples. A windmill generator, a nuclear
reactor, a pole vault jumper.
13. Match definition and type of energy:
Internal energy Stored in the chemical bonds among atoms
Chemical energy Due to electrical charges in motion
Nuclear energy Includes all the forms of energy inside a
body
Mechanical energy Energy transported by electromagnetic
waves
Thermal energy Due to atoms and molecules motion
Electrical energy Released during nuclear fusion or fision
Electromagnetic energy Energy that a body has because it moves.
14. Explain the difference between kinetic and potential energy.
15. Explain the principle of energy conservation. Why are not changes completely
efficient?