Both helium (He) and beryllium (Be) have two valence electrons.Whereas he represent a noble gas element,Be does no. Assign reason.

Both helium (He) and magnesium (Mg) have two valence electrons. He represents a noble gas element, but Mg does not. Assign reason.

All alkali metals have one valence electron, ns^(1) , outside the noble gas core except :

Give reason Electron affinity of noble gas elements is zero.

Most of the monatomic ions of the representative elements are obtained by removing all the valence electrons from the atoms of metallic elements. Once these atoms have lost their valence electrons, they have stable noble gas or pseudo noble gas configurations. Which of these elements forms a cation having pseudo noble gas configuration?

Name any two elements that have two electrons in their valence shell.

Write the general valence shell electronic configuration of noble gases (except He).

Na, Mg and Al are the elements having one, two and three valence electrons respectively. Which of these elements (i) has the largest atomic radius, (ii) is least reactive ? Justify your answer stating reason for each.