Helium atom has 2 electrons in its valence shell but its valency is not 2. Explain.

(a) The element helium has 2 electrons in its valence shell but its valency is not 2. Explain (b) Choose the isotopes from the following nuclie: (i)8p+8n,(ii) 8p+9n,(iii) 18p +22n ,(iv)20p+20n

An element has 8 electrons in the valence shell

Fluorine atom contains 7 electrons in the outermost shell. But its valency is '1'. Explain.

An element A has 2 electrons in its, fourth shell. State its valency

Helium is a noble gas with 2 electrons in its outermost shell. Its valency is 0.

Elements A has one electron in its valence shell and its principal quantum number is one & atom B has 5 electron in its valence shell and its principal quantum number for last electron is 3 so compound of A and B is

Select the correct answer from the choice in bracket to complete each sentence:- An element 'X' has six electrons in its outer or valence shell. Its valency is _________ [+2/-2/-1].

The noble gas having only two electrons in its valence shell is:

Element A has two electrons in its valence shell and its principle quantum number for last electron is 2 element B has four electrons in its valence shell and its principle quantum number for lastb electron is 2 element X has threee electrons in its valence shell and principle quantum number for last electron is 3 compounds XB and AB on hydrolysis give