Long Answer TypeA, B, C are three elements, B is an inert gas element other than helium; with this information, complete the table given below:
| Element | Atomic No. | No. of electrons in the valence shell | Group to which element belongs |
| A | Z - 1 | ||
| B | Z | ||
| C | Z+1 |
Also, explain the following:
(i) Electron gain enthalpy of element A has large negative value than that of C.
(ii) Ionisation enthalpy of element C is less than that of A.
(iii) Electron gain enthalpy of B is positive.
Define electronegativity. Explain the factors influencing electronegativity. How does it vary along periods and groups? what are its units?
Short Answer TypeExplain giving various reasons for the variation of electronegativity along a period and along a group.
(i) Variation of electronegativity in a period: In a period electronegativity increases in moving from left to right. This is due to the reason that nuclear charge increases whereas atomic radius decreases as we move from left to right in a period. Halogens have the highest value of electronegativity in their respective period.
(ii) Variation of electronegativity in a group: In a group, electronegativity decreases on moving down the group. This is due to the effect of increased atomic radius. For example among halogens, fluorine has the highest electronegativity.
Long Answer TypeWhat is the basic difference between the terms electronegativity and electron gain enthalpy?
Short Answer TypeHow would you react to the statement that the electronegativity of N on Pauling scale is 3.0 in all the nitrogen compounds?
Long Answer TypeThe valence of representative elements is either equal to the number of valence electrons or eight minus the number. What is the basis of their rule?
Short Answer TypePredict the formulae of the stable binary compounds that would be formed by the following pairs of elements:
silicon and oxygen
Predict the formulae of the stable binary compounds that would be formed by the following pairs of elements:
aluminium and bromine
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