The alkali metals have relatively low melting point. Which one of the following alkali metals is expected to have the highest melting point?

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Q: 67 (NDA-II/2015)
The alkali metals have relatively low melting point.
Which one of the following alkali metals is expected to have the highest melting point?

question_subject: 

Geography

question_exam: 

NDA-II

stats: 

0,11,13,11,4,1,8

keywords: 

{'alkali metals': [0, 0, 1, 2], 'highest melting point': [0, 0, 0, 1], 'low melting point': [0, 1, 1, 3], 'na': [0, 0, 2, 2]}

The question asks us to determine which alkali metal is expected to have the highest melting point. Alkali metals are a group of elements in the periodic table that are highly reactive and have only one valence electron.

Option 1: Lithium (Li) is the correct answer. Lithium has the highest melting point among the alkali metals. It has a melting point of about 180.54°C (356.97°F). Despite being the lightest alkali metal, lithium has a strong metallic bond, which contributes to its higher melting point compared to the other alkali metals.

Option 2: Sodium (Na) has a lower melting point compared to lithium. It has a melting point of about 97.72°C (207.9°F).

Option 3: Potassium (K) also has a lower melting point compared to lithium and sodium. It has a melting point of about 63.38°C (146.08°F).

Option 4: Rubidium (Rb) has the lowest melting point among the alkali metals. It has a melting point of about 39.31°C (102.8°F).

In summary, lithium has the highest melting point among the given options.