Chemistry Test Atomic Structure 2

Question 1

Which quantum number describes the shape of an atomic orbital?

Accepted Answer

Angular momentum quantum number (l)

Answer

The angular momentum quantum number (l) defines the shape of the orbital, with values 0, 1, 2, 3 corresponding to s, p, d, f orbitals.

Question 2

An atom has 17 protons and 18 neutrons. What is its mass number?

Accepted Answer

35

Answer

Mass number equals protons plus neutrons, so 17 + 18 = 35.

Question 3

Which of the following correctly describes isotopes?

Accepted Answer

Atoms with the same number of protons but different numbers of neutrons

Answer

Isotopes are atoms of the same element (same proton count) that differ in the number of neutrons.

Question 4

In Bohr's model of the hydrogen atom, what happens when an electron absorbs energy?

Accepted Answer

It jumps to a higher energy level

Answer

When an electron absorbs a photon of sufficient energy, it transitions to a higher (farther from nucleus) energy level.

Question 5

What is the maximum number of electrons that can occupy the third principal energy level (n=3)?

Accepted Answer

18

Answer

The maximum electrons per shell is given by 2n², and for n=3: 2(3)² = 18.

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