Question

A monatomic anion of unit charge contains 18 neutrons and 18 electrons find the atomic number mass number of the anion which is

Answer 1

atomic no.is 18  and mass is 36

Answer 2

Answer:

The anion is Chlorine with atomic number 17 and mass number 35.

Explanation:

Element:

• It is a periodic table's fundamental unit.
• Many elements in nature can produce cation or anion at different periods.
• A factor is used to classify a neutral element, which means it must have an equal amount of electrons and protons.
• Number of electrons = Number of protons.

Atomic number:

• The number of protons in an atom's nucleus is known as its atomic number.
• The identity of an element is determined only by the number of protons present; it is unaffected by the number of neutrons present. It is denoted by the letter Z.

Mass number:

• The total number of neutrons and protons in the nucleus is the mass number. It is denoted by the letter A and is written as,

• A = Z + no. of neutrons

Result:

Given that, Number of electrons = 18

Number of neutrons = 18

It is a monatomic anion with unit charge so, net charge = -1

Thus, we get,

Net charge = No. of protons – No. of electrons

−1 = x − 18x = 18 − 1 = 17protons

Thus, the number of protons = 17 which in fact is the atomic number of an element. Hence, the anion we are discussing about is chlorine i.e. Cl.

Now, the mass number is given as, A = Z + no. of neutrons

A = 17 + 18 = 35

Thus, mass number is 35.