Question

the atomic numbers of the three elements x,y & z are 2,6 and 10 respectivly then which two elements belong to the same group?​

Answer 1

Answer:

y and z

Explanation:

$\text{\large\underline{\orange{Solution:}}}$

We knows atomic numbers of three elements that are x, y and z = 2, 6 and 10 respectively.

We know, the element whose atomic no. is 2 = Helium (He),

$\:\:\:$ The element whose atomic no. is 6 = Carbon (C),

$\:\:\:$ The element whose atomic no. is 10 = Neon (Ne).

Let's try to do electronic configuration of these elements first.

{An element can have 2 or maximum 8 electrons in its outermost shell, to make it stable it will either loose or gain some electrons}

• He = 2 [It's outermost shell is already filled with 2 electrons, so the are stable]

Hence,the valency of helium is 0.

• C = 2, 4

Carbon is left can either loose 4 electrons or gain 4 electrons to make it stable.

Hence, valency of Carbon is 4.

• Ne = 2, 8 [It's outermost shell is also filled with 8 electrons, so it is stable]

Hence, valency of Neon is 0.

Conclusion - We saw that we have two elements whose valencies are 0 i.e, they are stable. They are, Helium and Neon.

$\sf{\underline{\underline{\therefore\:The\:two\:common\:elements\:are\:y\:and\:z\:i.e,\:He\:and\:Ne}}}$

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Note: Elements whose valencies are 0 or their outermost shell is filled with either 2 or 8 electrons are known as inert elements. Some more examples of inert elements are Argon (Ar), Krypton (Kr), Xenon (Xe), etc.