Llav
q3. an ion composed of which of these particles wo
a mass of approximately 16 amu and a charge of 2-?
(a) 8 protons and 8 electrons
(b) 8 protons, 8 neutrons, and 10 electrons
(c) 8 protons, 8 neutrons, and 8 electrons
(d) 8 protons, 8 neutrons, and 6 electrons

(b) 8 protons, 8 neutrons, and 10 electrons

Explanation:

The protons are positively charged while the electrons are negatively charged. The neutrons are neutral.

Mass of the atom is equal to number of protons plus the number of neutrons. Electrons are not counted because they are very light compared with protons and neutrons masses, so they are neglected.

(a) 8 protons and 8 electrons

- the charge will compensate each other so the atom is neutral

(b) 8 protons, 8 neutrons, and 10 electrons

- we two more electrons than the number of protons, so the atom will be an ion with a charge of 2- and a mass of 16 amu.

(c) 8 protons, 8 neutrons, and 8 electrons

- the charge will compensate each other so the atom is neutral

(d) 8 protons, 8 neutrons, and 6 electrons

- we have two more protons than the number of electrons, so the atom will be an ion with a charge +2 and a mass of 16 amu.