Exams › JEE Main › Chemistry

Lithium has a melting point of 181°C, which is nearly twice that of sodium at 98°C. This is mainly because

1. as we move down the group, hydration energy falls
2. as we move down the group, ionization energy falls
3. as we move down the group, cohesive energy falls
4. none of the above

Correct answer: as we move down the group, cohesive energy falls

Solution

Lithium has a higher melting point than sodium primarily due to its stronger cohesive energy, which is a result of its smaller atomic size and greater charge density, leading to stronger metallic bonding compared to sodium.

Related JEE Main Chemistry questions

• Which statement correctly describes how chemical reactivity changes down the group for alkali metals and halogens?
• Which of the following is a true peroxide?
• When zeolite, a hydrated sodium aluminium silicate, is used with hard water, which ions from the water replace the sodium ions in the zeolite?
• Among the following carbonates, which one is the least thermally stable?
• The solubility of carbonates falls as we move down the magnesium group because there is a reduction in the
• Which of the following salts fails to give any colour in a flame test?

⚔️ Practice JEE Main Chemistry free + battle 1v1 →