Question

An element T ,has Electronic configuration
2,8,5 and mass number 31.
(1)What is the group number?
(ii)What is the period number of T?
(iii) State the number of proton and neutron in T?

Answer 1

Answer:

ok ....................

Answer 2

Answer:

Answer

   Atomic number = Number of protons

Hence , number of protons in K atoms = 19

Number of neutrons = Mass number - Atomic number

Hence , number of neutrons in K atom = 39−19=20

Number of electrons = Number of protons

Hence , the number of electrons = 19

And electronic configuration of K atom = 2,8,8,1

Since K atom has 4 shells , hence it belongs to fourth period.

With one valence electron , it belongs to group 1

   Number of protons in P atom = 15

Number of neutrons in P atom = 31−15=16

Number of electrons in P atom = 15

And electronic configuration of P atom = 2,8,5

Since it has three shells , it belong to period 3 and with 5 valence electrons Phosphorous is found in five plus ten that is 15th group.

Mark me as brainliest