Oxygen has three isotopes, ¹⁶O, ¹⁷O, and ¹⁸O. The atomic number of oxygen is 8. How many protons and neutrons does each of the isotopes have?

Draw the ground-state electronic configuration for each of the following:

a. Mg

Chlorine has two isotopes, ³⁵Cl and ³⁷Cl; 75.77% of chlorine is ³⁵Cl, and 24.23% is ³⁷Cl. The atomic mass of ³⁵Cl is 34.969 amu, and the atomic mass of ³⁷Cl is 36.966 amu. What is the atomic mass of chlorine?

Name the element that corresponds to each electronic configuration.

a. 1s² 2s² 2p²

b. 1s² 2s² 2p⁴

c. 1s² 2s² 2p⁶ 3s² 3p³

d. 1s² 2s² 2p⁶ 3s² 3p⁵

Write the ground-state electronic configuration for chlorine (atomic number 17), bromine (atomic number 35), and iodine (atomic number 53).

a. How many protons do the following species have?

b. How many electrons does each have?

1. Na⁺
2. Ar
3. Cl^-

Write the electronic configurations of the third-row elements shown in the partial ­periodic table in Figure 1-6.

Chlorine exists as one of two isotopes with atomic masses of 34.969 amu (³⁵Cl) and 36.966 amu (³⁷Cl) . Calculate the relative abundance of ³⁵Cl and ³⁷Cl based on the average atomic mass of 35.453 amu.

Bromine-79 (50.7% abundance) has an atomic mass of 78.918 amu, whereas bromine-81 (49.3% abundance) has an atomic mass of 80.916 amu. From these data, calculate the average atomic mass of bromine that you would expect to see in the periodic table.