Question

The teacher wrote the electronic sequence 2, 8, 7 of the atom of an element. What is the atomic number of this element? A) 7 B) 2 ((C) 17​

Answer 1

ANSWER :-

Electronic configuration

2 , 8 , 7

total number of electrons = 2 +  8 + 7 =  17

Atomic number = number of electrons = 17

therefore,

option ( c ) is correct