Electrochemistry Practice Problems

1. An atom with the electron configuration 1s²2s²2p⁶3s²3p⁶3d⁵4s² has an incomplete

1. 2p sublevel 
2. Second principal energy level 
3. Third principal energy level 
4. 4s sublevel

2. What is the total number of electrons in a completely filled fourth principal level?

1. 8 
2. 10 
3. 16 
4. 32

3. The characteristic bright line spectrum of an element is produced when its electrons

1. Form a covalent bond 
2. Form an ionic bond 
3. Move to a higher energy state 
4. Move to a lower energy state

4. Which emanation has no mass and no charge?

1. Alpha 
2. Beta 
3. Gamma 
4. Neutron

5. In which system do molecule-ion attractions exist?

1. NaCl(aq) 
2. NaCl(s) 
3. C₆H₁₂O₆(aq) 
4. C₆H₁₂O₆(s)

6. A particle accelerator can increase the kinetic energy of

1. An alpha particle and a beta particle 
2. An alpha particle and a neutron 
3. A gamma ray and a beta particle 
4. A neutron and a gamma ray

7. What is the total number of electrons needed to completely fill all of the orbitals in an atom’s second principal energy level?

1. 16 
2. 2 
3. 8 
4. 4

8. An atom in an excited state can have an electron configuration of

1. 1s²2s² 
2. 1s²2p¹ 
3. 1s²2p² 
4. 1s²2s²2p⁵

9. Compared to the charge and mass of a proton an electron has

1. The same charge and smaller mass 
2. The same charge and the same mass 
3. The opposite charge and smaller mass 
4. The opposite charge and the same mass

10. What is the total number of sublevels in the fourth principal energy level?

1. 1 
2. 2 
3. 3 
4. 4

11. Which atom in the ground state has only one unpaired electron in its valence shell?

1. Aluminum 
2. Silicon 
3. Phosphorus 
4. Sulfur

12. The shape and bonding of a diatomic bromine molecule are best described as

1. Symmetrical and polar 
2. Symmetrical and nonpolar 
3. Asymmetrical and polar 
4. Asymmetrical and nonpolar

13. What is the oxidation number of sulfur in H₂SO₄?

1. 0 
2. -2 
3. +6 
4. +4

14. When alpha particles are used to bombard gold foil, most of the alpha particles pass through undeflected. This result indicates that most of the volume of gold atom consists of

1. Neutrons 
2. Protons 
3. Deuterons 
4. Unoccupied space

15. When an alpha particle is emitted by an atom, the atomic number of the atom will

1. Decrease by 2 
2. Increase by 2 
3. Decrease by 4 
4. Increase by 4

16. Which of the following element has the corresponding valence subshell of 3p⁴? Atomic numbers are listed next to the elements.

1. Aluminum 13 
2. Silicon 14 
3. Sulfur 16 
4. Chlorine 17

17. Which of the following element has the corresponding valence subshell of 3p⁶? Atomic numbers are listed next to the elements.

1. Sulfur 16 
2. Chlorine 17 
3. Argon 18 
4. Potassium 19

18. Which of the following element has the corresponding valence subshell of 3s¹? Atomic numbers are listed next to the elements.

1. Neon 10 
2. Sodium 11 
3. Magnesium 12 
4. Aluminum 13

19. Which of the following element has the corresponding valence subshell of 2p⁴? Atomic numbers are listed next to the elements.

1. Nitrogen 7 
2. Oxygen 8 
3. Neon 10 
4. Magnesium 12

20. What is the maximum number of electrons that can be found in the orbital denoted by the letter f?

1. 10 
2. 14 
3. 16 
4. 18

Answer Key

1. C 
2. D 
3. D 
4. C 
5. A 
6. A 
7. C 
8. B 
9. C 
10. D 
11. A 
12. B 
13. C 
14. D 
15. A 
16. C 
17. C 
18. B 
19. B 
20. B