Week 81. Select the particle or particles that account for more than 99.99% of the mass of atoms other than hydrogen.

A. Protons onlyB. Electrons onlyC. Protons and neutronsD. Electrons and neutrons

2. Which of the following elements has the fewest total number of electrons?

A. Nitrogen (N)B. Sodium (Na)C. Helium (He)D. Lead (Pb)

3. Select the best statement about different isotopes of an element.

A. Same number of protons and same number of neutrons.

B. Same number of protons but different number of neutrons.

C. Different number of protons but same number of neutrons.

D. Different number of protons and different number of neutrons.

4. An atom of neon (Ne) has 10 protons, 10 neutrons, and 10 electrons.

What is the atomic mass of neon?

A. 0 amuB. 10 amuC. 20 amuD. 30 amu

5. Which statement describes how hydrogen-1 and hydrogen-2 differ? A. Hydrogen-2 has more protons than hydrogen-

1B. Hydrogen-2 has more electrons than

hydrogen-1C. Hydrogen-2 has a higher atomic number than

hydrogen-1D. Hydrogen-2 has more neutrons and more

mass than hydrogen-1.

6. Which of the following is an element?

A. WaterB. OzoneC. OxygenD. Carbon dioxide

7. Which of the following is NOT a property of most metals?

A. Solid at room temperatureB. Have lusterC. Conduct heat and electricity wellD. Do not react readily with any other elements

8. How many electrons fit into the first energy level or shell?

A. 1B. 2C. 4D. 8

9. Which of the following is NOT true of noble gases?

A. Except for helium, they have 8 electrons in their outer shell

B. They do not react readily with other elements

C. They usually exist as ionsD. They are in Group 18 (VIIIA)

10. All of the elements in the halogen family

A. Need to give up one electron to become stable

B. Need to gain one electron to become stableC. Do not react at all with other elementsD. Do not need to gain one electron to become

stable.