Assertion (A): | A reaction can have zero activation energy. |
Reason (R): | The minimum extra amount of energy absorbed by reactant molecules so that their energy becomes equal to threshold value, is called activation energy. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | (A) is false but (R) is true. |
1. | 2. | ||
3. | 4. |
A: | Atoms of all elements are composed of two fundamental particles. |
B: | \(9.10939 \times 10^{-31} \mathrm{~kg} \text {. }\). | The mass of the electron is
C: | All the isotopes of a given element show same chemical properties. |
D: | Protons and electrons are collectively known as nucleons. |
E: | Dalton's atomic theory regarded the atom as an ultimate particle of matter. |
1. | B, C and E only | 2. | A, B and C only |
3. | C, D and E only | 4. | A and E only |
A. | dipole - dipole forces |
B. | dipole-induced dipole forces |
C. | hydrogen bonding |
D. | covalent bonding |
E. | dispersion forces |
1. | |
2. | |
3. | |
4. |
1. | Mg plays role in neuromuscular function and interneuronal transmission. |
2. | The daily requirement of Mg and Ca in the human body is estimated to be 0.2-0.3 g. |
3. | All enzymes that utilize ATP in phosphate transfer require Ca as the cofactor. |
4. | The bone in the human body is an inert and unchanging substance. |