Question

Enter the number of electrons in each energy level (shell) for each of the elements. If the energy level does not contain any electrons, enter a 0.0. It may help to refer to the periodic table.

He:

?=1:

n=2:

n=3:

n=4:

F:

n=1:

n=2:

n=3:

n=4:

P:

n=1:

n=2:

n=3:

n=4:

Ca:

n=1:

n=2:

n=3:

n=4

What is the neutral atom that has its first two energy levels filled, has 55 electrons in its third energy level, and has no other electrons? Enter the name of the element, not the abbreviation.

element name:

Answer 1

Ans :

The number of electrons in the energy levels of the atom can be determined on the basis of their electron configurations.

So here :

He :

n = 1 : 2

n = 2 : 0.0

n = 3 : 0.0

n = 4 : 0.0

F :

n = 1 : 2

n = 2 : 7

n = 3 : 0.0

n = 4 : 0.0

P :

n = 1 : 2

n = 2 : 8

n = 3 : 5

n = 4 : 0.0

Ca :

n = 1 : 2

n = 2 : 8

n = 3 : 8

n = 4 : 2

If first two energy levels are filled , then the total number of electrons in the atom of this element will eb :

= 2 + 8 + 55 = 65 electrons

The neutral atoms gets its atomic number from the number of electrons , so here the element with atomic number 65 is :

= Terbium