Much of the study of chemistry involves the interactions between the electrons of different atoms. It is important, therefore, to understand the arrangement an atom's electrons. This ten-question multiple choice chemistry practice test deals with the concepts of electronic structure, Hund's Rule, quantum numbers, and the Bohr atom.

Answers to each question appear at the end of the test.

Question 1

The total number of electrons that can occupy the principle energy level n is:
(a) 2
(b) 8
(c) n
(d) 2n²

Question 2

For an electron with angular quantum number ℓ = 2, the magnetic quantum number m can have
(a) An infinite number of values
(b) Only one value
(c) One of two possible values
(d) One of three possible values
(e) One of five possible values

Question 3

The total number of electrons allowed in a ℓ = 1 sublevel is
(a) 2 electrons
(b) 6 electrons
(c) 8 electrons
(d) 10 electrons
(e) 14 electrons

Question 4

A 3p electron can have possible magnetic quantum number values of

(a) 3 and 6

(b) -2, -1, 0, and 1

(c) 3, 2, and 1

(d) -1, 0, and 1

(e) -2, -1, 0, 1, and 2

Question 5

Which of the following set of quantum numbers would represent an electron in a 3d orbital?
(a) 3, 2, 1, -½
(b) 3, 2, 0, +½
(c) Either a or b
(d) Neither a nor b

Question 6

Calcium has an atomic number of 20. A stable calcium atom has an electronic configuration of
(a) 1s²2s²2p⁶3s²3p⁶4s²
(b) 1s²1p⁶1d¹⁰1f²
(c) 1s²2s²2p⁶3s²3p⁶3d²
(d) 1s²2s²2p⁶3s²3p⁶
(e) 1s²1p⁶2s²2p⁶3s²3p²

Question 7

Phosphorus has an atomic number of 15. A stable phosphorus atom has an electronic configuration of
(a) 1s²1p⁶2s²2p⁵
(b) 1s²2s²2p⁶3s²3p³
(c) 1s²2s²2p⁶3s²3p¹4s²
(d) 1s²1p⁶1d⁷

Question 8

The electrons with principle energy level n = 2 of a stable atom of boron (atomic number = 5) have an electron arrangement of
(a) ( ↑ ↓ ) ( ↑  ) (  ) (  )
(b) ( ↑   ) ( ↑   ) ( ↑   ) (     )
(c) (     ) ( ↑   ) ( ↑   ) ( ↑   )
(d) (     ) ( ↑ ↓ ) ( ↑   ) (     )
(e) ( ↑ ↓ ) ( ↑ ↓ ) ( ↑   ) ( ↑   )

Question 9

Which of the following electron arrangements does not represent an atom in its ground state?
(1s)      (2s)               (2p)              (3s)
(a) ( ↑ ↓ )   ( ↑ ↓ )   ( ↑ ↓ ) ( ↑ ↓ ) ( ↑ ↓ )   ( ↑   )
(b) ( ↑ ↓ )   ( ↑ ↓ )   ( ↑ ↓ ) ( ↑ ↓ ) ( ↑ ↓ )   ( ↑ ↓ )
(c) ( ↑ ↓ )   ( ↑ ↓ )   ( ↑ ↓ ) ( ↑   ) ( ↑   )
(d) ( ↑ ↓ )   ( ↑ ↓ )   ( ↑ ↓ ) ( ↑ ↓ ) (     )

Question 10

Which of the following statements is false?
(a) The greater the energy transition, the greater the frequency
(b) The greater the energy transition, the shorter the wavelength
(c) The higher the frequency, the longer the wavelength
(d) The smaller the energy transition, the longer the wavelength

Answers

1. (d) 2n²
2. (e) One of five possible values
3. (b) 6 electrons
4. (d) -1, 0, and 1
5. (c) Either set of quantum numbers would express an electron in a 3d orbital
6. (a) 1s²2s²2p⁶3s²3p⁶4s²
7. (b) 1s²2s²2p⁶3s²3p³
8. (a) ( ↑ ↓ ) ( ↑   ) (     ) (     )
9. (d) ( ↑ ↓ )  ( ↑ ↓ )  ( ↑ ↓ ) ( ↑ ↓ ) (     )
10. (c) The higher the frequency, the longer the wavelength