Question

deuterium is an isotope of hydrogen. it has a mass number of two. which describes a deuterium atom? a. a nucleus of one proton and one neutron, which is orbited by one electron b. a nucleus of one proton, which is orbited by one neutron and one electron c. a nucleus of one neutron, which is orbited by one electron d. a nucleus of two neutrons which is orbited by two electrons

Explanation:

Hydrogen - 1 (protium) has 1 proton. Deuterium is an isotope of hydrogen. Isotopes have the same number of protons but different numbers of neutrons. For deuterium with a mass number of 2, mass number = number of protons+number of neutrons. Since hydrogen always has 1 proton, deuterium has 1 proton and 1 neutron in its nucleus, and 1 electron orbits the nucleus to maintain electrical neutrality.

Answer:

A. a nucleus of one proton and one neutron, which is orbited by one electron