What is meant by the term 'electrovalency'. State why Na [at. no. 11] has a electropositive valency of +1 and Cl [ at. no. 17] an electronegative valency of -1.

What is meant by the terms (1) amplitude (2) frequency, of a wave ?

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.

What type of bonds are expected to be formed between atoms having electronegativity difference equal to 1.1,

What is meant by a paramagnetic substance ? State Curie.s law. What is the value of magnetic susceptibility of Aluminium if its relative permeability is 1-000022 ?

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.

With reference to formation of compounds from atoms by electron transfer - electrovalency, state the basic steps in the conversion of sodium & chlorine atoms to sodium & chloride ions leading to the formation of the compound - sodium chloride. [electronic configuration of: Na = 2,8,1 & Cl = 2,8,7]

Consider the following elements B C F Cl N O If x,y and z are the number of elements having more electron affinity (Ea_(1)) than nitrogen, the number of elements having ionisation energy more than that of Na and the number of elements having electronegativity more than (or) almost equal to N respectively, find x+y+z . Fill your answer as sum of digit (excluding decimal places) till you get the single digit answer.

What is the valence shell electronic configuration of group 1 elements?

With reference to period 3 of the periodic table - State: The number of electrons in the penultimate shell of the element with valency -1.

Sodium and aluminium have atomic numbers 11 and 13, respectively. They are separated by one element in the periodic table, and have valencies 1 and 3 respectively. Chlorine and potassium are also separated by one element in the periodic table (their atomic numbers being 17 and 19, respectively) and yet both have valency 1. Explain.