The trend of atomic radius in a period and a group is :
1. | Generally decreases from right to left across a period and increases down a group. |
2. | Generally increases from left to right across a period and decreases down a group. |
3. | Generally decreases from left to right across a period and increases down a group. |
4. | Generally remains same from left to right across a period and increases down a group. |
The energy of an electron in the ground state of the hydrogen atom is . The ionization enthalpy of atomic hydrogen in terms of J is:
1. 2.81 × 106 J mol
2. 1.31 × 106 J mol
3. 2.31 × 106 J mol
4. 1.81 × 106 J mol
The first ionization enthalpy values (in kJ mol–1) of group 13 elements are :
B | Al | Ga | In | Tl |
801 | 577 | 579 | 558 | 589 |
The explanation for the deviation from the general trend can be -
1. Ga has lower ionization enthalpy than Al.
2. Ga has higher ionization enthalpy than Al.
3. Al has higher ionization enthalpy than Ga.
4. Ga has a lesser valence electron than Al.
An element with higher negative electron gain enthalpy in the given pair is:
(i) O or F (ii) F or Cl
1. O, Cl
2. F, F
3. O, F
4. F, Cl
The basic difference between the electron gain enthalpy (Ea) and electronegativity (EN) is:
1. | Ea is the tendency to lose electrons, while EN is the tendency to repel the shared pairs of electrons. |
2. | Ea is the tendency to gain neutrons, while EN is the tendency to attract the shared pairs of electrons. |
3. | Ea is the tendency to donate electrons, while EN is the tendency to attract the shared pairs of molecules. |
4. | Ea is the tendency to gain electrons, while EN is the tendency to attract the shared pairs of electrons. |
The statement that "the electronegativity of N on the Pauling scale is 3.0 in all the nitrogen compounds" is incorrect because:
1. | Electronegativity of an element is a variable property. |
2. | Pauling scale is not used to measure electronegativity. |
3. | The electronegativity of N on the Pauling scale is 12.0 |
4. | None of the above. |
The correct statement about the radius of a species is :
1. | Radius increases during cation and anion formation. |
2. | Radius increases during anion formation and decreases during cation formation. |
3. | Radius decreases in cation as well as anion. |
4. | Radius decreases during anion formation and increases during cation formation. |
The values of the first ionization enthalpies for two isotopes would be:
1. | Same. |
2. | Different. |
3. | Same values but positive for the first and negative for the second. |
4. | Same values but negative for the first and positive for the second. |
The reactivity of alkali metals increases, whereas halogen decreases down the group, because:
1. | On moving down, ionization enthalpy decreases in group 1 while the electron gain enthalpy becomes less negative in group 17. |
2. | On moving down, ionization enthalpy increases in group 1 while the electron gain enthalpy becomes less negative in group 17. |
3. | On moving down, ionization enthalpy increases in group 1 while the electron gain enthalpy becomes less positive in group 17. |
4. | On moving down, ionization enthalpy decreases in group 17 while the electron gain enthalpy becomes less negative in group 1. |
The general outer electronic configuration of s, p, d , and f-block elements respectively would be :
1. | ns1-2, nd2np1-6, (n-1)d1-10np0-2, (n-2)f1-14(n-1)d0-10ns2 |
2. | ns1-2, ns2np1-6, (n-1)f1-10ns0-2, (n-2)g1-14(n-1)d0-1ns2 |
3. | ns1-2, ns2np1-6, (n-1)d1-10ns1-2, (n-2)f1-14(n-1)d0-1 ns2 |
4. | np1-2, nd2np1-6, (n-1)d1-10ns0-2, (n-2)f1-14(n-1)d0-10ns2 |