Question

The colour of hydrogen is:
a.) Yellow
b.) Orange
c.) Red
d.) None of the above

Answer 1

Hint: Hydrogen is an element of group 1. The atomic number of hydrogen is also 1. It is the lightest element in the periodic table.

Complete step by step answer:
Hydrogen is a chemical element with atomic number 1. It is represented by H. Its standard atomic weight is 1.008 and is the lightest element in the periodic table. Hydrogen is the most abundant chemical substance in the universe, which constitutes roughly 75% of all the baryonic mass.
Hydrogen also has three isotopes: protium, deuterium and tritium. Protium is the most common isotope of hydrogen which has one proton and no neutron. Also, non-remnant stars are mainly composed of hydrogen in the plasma state.
At standard temperature and pressure, hydrogen is a colourless, odourless, tasteless, non-toxic, non-metallic, highly combustible diatomic gas. Its molecular formula is \[{H_2}\]. Hydrogen readily forms covalent compounds with most non-metallic elements. Thus, most of the hydrogen on Earth exists in molecular forms such as water or organic compounds.
Hydrogen also plays an important role in acid–base reactions because most acid-base reactions involve the exchange of protons between soluble molecules.

Hence, the colour of hydrogen is colourless.
Therefore, the correct answer is (D) None of the above.

Note: Remember that the liquid form of hydrogen is also colourless. To liquify hydrogen, it is cooled below its critical temperature of 33 K.