Question

A se ion has a mass number of 77
and a charge of −2
. Determine the number of neutrons, protons, and electrons in this ion.

Answer 1

Answer: The number of protons are 34, number of neutrons are 43 and number of electrons are 36 in the given Se ion

Explanation:

The atom consists of 3 subatomic particles:

• Protons: They are positively charged particles present in the nucleus of an atom.
• Electrons: They are negatively charged particles present in the orbits around the nucleus of an atom.
• Neutrons: They are neutral particles present in the nucleus of an atom.

The mass number is the sum of the number of protons and number of neutrons in the nucleus of an atom. These are known as nucleons

The atomic number is defined as the number of electrons or number of protons present in an atom.

We are given:

A Se ion having mass number 77

Atomic number of Se = 34

Number of protons = 34

Number of neutrons = 77 - 34 = 43

Number of electrons = Atomic number - Charge

Charge = -2

Number of electrons = [34 - (-2)] = [34 + 2] = 36

Hence, the number of protons are 34, number of neutrons are 43 and number of electrons are 36 in the given Se ion