Question

the description of atomic particles of two elements X and Y is given below
X-protons=8,neutrons=8,electrons=8
Y-protons=8,neutrons=9,electrons=8
1)what is the atomic number of X?
2)what is the mass number of Y?
3)what is the relation between X and Y?
4)write the electronic configuration of x?
5)what is its valency?

Answer 1

1) atomic number =8
2)mass number =17
3) sorry I didn't know this one
4)electronic configuration =2,6
5)valency =6

Answer 2

1) Atomic number = Neutrons + Protons
Atomic number of X is 8+8=16
2) Mass Number = Neutrons +Protons +
Electrons
Mass no. of Y is 8+8+9=25
3) They both lie in same period in periodic table. Both are non-metal.
4)Electronic configuration of X is 2,8,6.
5) It is a non-metal therefore it's valency is valency = 8-valence electrons.
Therefore it's valency is 8-6=2