Question

Electronic configuration of a element is 2, 8, 7. Find the element from following which chemical property is resemble to the element. *
फ्ल्युओरिन / Fluorine (F)
कार्बन / Carbon (C)
हेलियम / Helium (He)
फॉस्फरस / Phosphorus (P)​

Answer 1

Answer:

The number of electrons present in an atom is

⇒ 2+8+7 = 17.

Therefore, the atomic number of this element is 17 and the element is chlorine.

Cl (Z = 17) = 1s2 2s2 2p6 3s2 3p5

(b)

Answer: (b) F(9)

It would be chemically similar to F(9) with configuration as 2, 7.

Electronic configuration of Fluorine is,

F (Z = 9) = 1s2 2s2 2p5

Answer 2

The correct option is Fluorine.

• Electronic configuration of a element is 2, 8, 7. So, the atomic number of the element is (2+8+7=17).
• Chlorine has atomic number 17 so, the element is chlorine.
• Chlorine is a group 17 element in periodic table. It will show similar chemical property to the other elements of this group.
• Fluorine,Iodine,At are group 17 element and show same chemical property to chlorine.