Question

select the subatomic composition that describes an arsenide ion (as³⁻) with a mass number of 75. refer to a periodic table. 42 protons, 33 neutrons, 36 electrons 33 protons, 42 neutrons, 33 electrons 33 protons, 42 neutrons, 36 electrons 42 protons, 33 neutrons, 33 electrons

Explanation:

Step1: Determine atomic number of As

Arsenic (As) has an atomic number of 33, which means number of protons = 33.

Step2: Calculate number of neutrons

Mass number = number of protons + number of neutrons. Given mass - number = 75 and protons = 33, then neutrons = 75 - 33=42.

Step3: Determine number of electrons

The ion is $As^{3 - }$, which means it has gained 3 electrons. Neutral As has 33 electrons, so $As^{3 - }$ has 33 + 3=36 electrons.

Answer:

33 protons, 42 neutrons, 36 electrons