Question

question number twenty to twenty four. I promise I will mark it brilliant

Answer 1

Ans 20: the temperature at which a solid melts it's called melting point and the temperature at which a liquid boils it's called boiling point.

Ans 21: Ca=ec:2,8,8,2 ,ve=2 ,valency=+2
P:2,8,4 , ve=4 ,valency=-4
Cl:2,8,7, ve=7, valency= -1
Ans 22 (don't know)
Ans 23: K
Na
Ca
Mg
Al
Zn
Fe
Pb
H
Cu
Pt
Au

Ans24: mass can neither be created nor destroyed


HOPE THIS HELPED YOU