Question

An atom of an element has 3 electrons in outermost M shell state the

atomic number

electronic configuration .

number of protons

valency

name of the element..

Answer 1

Answer:

• No. of electrons in K shell = 2
• No. of electrons in L shell = 8
• No. of electrons in M shell = 3 (Given)

Total No. of electrons = 2+8+3 = 13

• Atomic No. = Total electrons = Z = 13

• Electronic Configuration =

$1 {s}^{2} \: 2 {s }^{2} \: 2 {p}^{6 \: } 3 {s}^{2} \: 3 {p}^{1}$

• No. of protons = Atomic No. = 13

In M shell maximum 8 electrons can be filled

• So, Valency = 8 - 3 = 5
• Name of the element = ALUMINIUM