Question

An atom has electronic configuration 2, 8, 5 then,
(a)What is the atomic number of this element?
(b)To which of the following elements would it be chemically similar 7N, 9F, 18Ar?​

Answer 1

Answer:

a,_atomic number of this element is 15.

B_7N is chemically similar to this element.

Answer 2

The atomic number is 15 and the element chemically represents Nitrogen(N).

• The Electronic configuration is defined as the arrangement of electrons of an atom or molecule in a particular order. A particular order is followed for filling the electrons in the s,p,d, and f shells.
• The sum of total electrons in the electronic configuration is equal to the total number of electrons of an atom or molecule. For example, 1s2 2s2 electronic configuration implies there are a total of 4 electrons.
• It is given that the atom has electronic configurations 2,8, and 5. Hence the sum of the electrons will be the total number of electrons of the element. 2+8+5 = 15. Hence, the total number of electrons is 15.
• The total number of electrons in the neutral state is equal to the atomic number of the element. Hence, the atomic number of the element is 15. The element name is Phosphorous.
• The elements which belong to the same group of the periodic table generally have the same properties. For example, all the elements of group I A have the same chemical properties.
• Phosphorous belongs to the V A group hence it contains similar chemical properties to Nitrogen.

Therefore, the atomic number of the element is 15 and it has similar chemical properties with Nitrogen.