Atomic Structure Practice Problems

There are three stable isotopes of oxygen having mass ­numbers 16, 17 and 18. Determine the number of neutrons and protons in each of these.

Elements under the same group in the periodic table exhibit the same chemical properties and reactivity. Explain why.

What is the electronic configuration of chlorine (Cl)?

Correct the mistake in the diagram for the following erroneous electron configuration of nitrogen (N).

What rule is not followed by the one who drew the following incorrect electron configuration of nitrogen (N).

An unknown element has two stable isotopes, ⁵⁰X, and ⁵¹X. The relative abundance of these isotopes is 0.25%, and 99.75% respectively. ⁵⁰X has an atomic mass of 49.947 while ⁵¹X has an atomic mass of 50.943. Determine the atomic mass and identity of X.

Write the complete ground state electronic configuration of Aluminum (Al).

Write the complete ground state electronic configuration of N^3-.

Give the complete ground state electronic configuration for the two elements having atomic numbers 8 and 16.

Determine the number of valence electrons in the atoms of Oxygen and Sulfur.

Nitrogen has two relatively stable isotopes: ¹⁴N and ¹⁵N. Determine the number of protons and neutrons in each isotope. (Recall: nitrogen has an atomic number of 7.)

How many protons and electrons do the following species have?

a. K⁺

b. Ne

c. O^2–

Which of the following sets of elements matches with the following set of electronic configurations [1s² 2s¹], [1s² 2s² 2p⁵], [1s² 2s² 2p⁶] and [1s² 2s² 2p⁶ 3s²]?