Valency is the number of hydrogen atoms which can combine with (or displace) one atom of the element (or radical] forming a compound'. With reference to the above definition of valency, state the valency of chlorine in hydrogen chloride, giving reasons.

One atom of hydrogen combines with one atom of chlorine and so the valency of chlorine is ……………… .

True or False: Valency is the number of protons an atom can donate or accept to form a chemical bond with another atom.

The atomic number of an element which can not show the oxidation state of +3 is-

Define the term valcney. With reference to water and ammonia as compounds respectively, state the valency of oxygen & nitrogen. Magnesium [2,8,2] has valency 2^(+) . Give reasons.

Valency is also the number of electrons - donated or accepted by an atom so as to achieve stable electronic configuration of the nearest noble gas'. With reference to this definition - a] State what is meant by 'stable electronic configuration'. b] State why the valency of- (i) sodium, magnesium & aluminium is +1,+2& +3 respectively. ii] chorine, oxygen & nitroge is: -1, -2 & -3 respectively.

The valency of an element A is 3 and that of element B is 2. Write the formula of the compound formed by the combination of A and B.

An element X has a mass number 4 and atomic number 2. Write the valency of this element.

The configuration of the valence orbital of an element with atomic number 22 is

Name the type of chemical bond formed by a complete transfer of electrons from the valence shell of one atom to the valence shell of another atom.

What happens to number of valence electrons in atoms of elements as we go down a group of the periodic table ?