Question

1. Five atoms are labelled V to Z
Atoms
Mass Number
Atomic Number
V
40
20
W
19
9
X
7
3
Y
16
8
Z
28
14
i]
Which one of these atoms (1) contains 7 protons; (2) has an electronic configuration 2,7? [Z, W]
ü] Write down the formula of the compound formed by atoms X and Y. [X2Y]
1989
Flemento​

Answer 1

No. of protons = atomic number.

Atom W has an electronic configuration of 2,7.

Atoms X and Y will form XY2