unit1 lesson3 prep1 part1

I . The symbol of copper atom is.............................................

• a. C

• b. co

• c. Cu

• d. Ca

2. The chemical symbol of nitrogen atom is.................................

• a. Na

• b. No

• c. N

• d. Ne

3. Pb is the symbol of .................................atom

• a. phosphorus

• b. bromine

• c. lead

• d. potassium

4. Silver is symbolized by.....................................

• a-Hg

• b. Au

• c. cu

• d. Ag

5. The atom nucleus contains.....................

• a. protons and neutrons.

• b. protons and electrons.

• c. neutrons and electrons.

• d. protons, neutrons and electrons.

6- .................................................are neutral particles exist in the nucleus.

• a. Protons

• b. Molecules

• c. Neutrons

• d. Electrons

7-The atomic number of the atom of an element equals the.............................

• a. number of protons revolving around the nucleus.

• b. number of neutrons in the nucleus.

• c. number of electrons in the nucleus.

• d. number of protons in the nucleus.

8. The sum of the numbers of protons and neutrons in the nucleus of the atom is known as.........................

• a. atomic number.

• b. mass number.

• c. valency.

• d. density.

9. The mass of the atom is concentrated in the..............................................

• a. protons.

• b. nucleus.

• c. neutrons.

• d. electrons.

10. Sodium atom (23Na) has a number of neutrons equals.........................

• a-11

• b. 23

• c. 12

• d. 34