Question

Which of the given elements a,b, c, d and e with atornic number 2,3,7, l0 and 30 respectively belong to the same period ?

Answer 1

HEY MATE YUR ANSWER IS....

ATOMIC NUMBER 2 ----> HELIUM

ATOMIC NUMBER 3 -----> LITHIUM

ATOMIC NUMBER 7 ----> NITROGEN
ATOMIC NUMBER 10 -->NEON
ATOMIC NUMBER 30 --> ZINC...

HOPE IT HELPS YOU..

PLSEE MARK IT AS BRAINLIEST......

Answer 2

Given elements : a , b , c , d and e with the atomic number 2 , 3 , 7 , 10 and 30 respectively.

Atomic number of a = 2

Electronic configuration of a = { 2 }

Element a has only one energy shell with a stable configuration.

Atomic number of b = 3

Electronic configuration of b = { 2 , 1 }

Element b has 2 energy shells.

Atomic number of c = 7

Electronic configuration of c = { 2 , 5 }

Element c has 2 energy shells.

Atomic number of d = 10

Electronic configuration of d = { 2 , 8 }

Element d has 2 energy shells.

Atomic number of e = 30

Electronic configuration of e = { 2 , 8 , 18 , 2}

Element e has 4 energy shells.

From the properties of periodic table, we know  that the elements belonging to a same group have same number of energy shells.

Here, in the question, the elements b , c and d have 2 energy shells, while a has only one energy shell and e has 4 energy shell.

And therefore, elements b , c and d belong to the same period.