Question

In which of the following properties hydrogen does not show similarity with alkali metals?
A. Electromotive character
B. Reducing nature
C. Electronic configuration(ns$^{1}$)
D. Diatomic nature of molecule

Answer 1

Hint: This question is based on the properties characterised by the elements in the periodic table. The position of hydrogen is still undecided due to its resemblance with the elements of group I-A, and group VII-A, belongs to alkali metals, and halogens respectively. Compare the hydrogen with the properties, and dissimilarity would be known with the alkali metals.

Complete step by step answer:
First, let us know about hydrogen. As mentioned hydrogen is similar to alkali metals, and halogens; but it is neither an alkali, nor a halogen.
Now, if we talk about the given options, let us discuss the electronic configuration.
If we look at the periodic table, it is placed in the group I-A due to its electronic configuration, it has one electron in its valence shell, and alkali metals like Li, Na, Mg too has one electron.
Even both alkali metals, and hydrogen are considered to be good reducing agents.
Now, if we talk about the diatomic nature, then we know that the alkali metals do not exist as diatomic in nature, this property of hydrogen is similar to the halogen group.
If we talk about the electromotive character, it describes the dissociation of dissolving. Consider we have sodium chloride compound, on dissolving it dissociates into sodium, and chloride ions. This property is exhibited by hydrogen too.
In the last, we can conclude that the diatomic nature of molecules is not similar to the alkali metals.
Hence, the correct option is (D).

Note: Don’t get confused, while comparing the properties of hydrogen, and alkali metals. Look at the properties, according to the given options one by one. Remember first the electronic configuration should be compared, so that we can differentiate between their groups, and properties according to the periodic table.