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.
Long Answer TypeWhat is the basic difference between the terms electronegativity and electron gain enthalpy?
The main points of difference are as:
| Electronegativity | Electrogain enthalpy |
| 1. It is the relative tendency of an atom in a molecule to attract the share pair fo electron towards itself in a covalent bond. | 1. It is the tendency of an isolated gaseous atom to attract an electron to form a negative ion. |
| 2. It is a number and has no units. | 2. It is measured in electron volts/atom or kJ mol-1. |
| 3. It is the property of a bonded atom. | 3. It is a property of an isolated atom. |
| 4. Electronegativity values are only the comparative values. | 4. Electron affinity values are the actual values. |
| 5. It changes regularly in a period or group. | 5. It does not change regularly in a period or a group. |
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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