Question

Which one of the following pairs of metals constitutes the lightest metals and heaviest densest metal, respectively?
A. Lithium and Mercury
B. Lithium and Osmium
C. Aluminium and Mercury
D. Aluminium and Osmium

Answer 1

Hint: The chemical which loses electrons very easily are called metals. Lightest metal means it should have low atomic number and less density and heaviest metal means the metal should have great weight and should have high density.

Complete step by step answer:
- In the question it is asked to find the pairs of metals constitutes the lightest metals and heaviest densest metal.
- Lithium is an atom having an atomic number of 3 and it is going to be denoted with a symbol Li.
- Lithium metal is soft and comes under alkali metals and white in color.
- Under standard conditions lithium is the lightest metal with a density of 0.53 kg/L.
- Osmium is an atom having an atomic number of 76 and it is going to be denoted with a symbol Os.
- Osmium metal is the heaviest metal present on the earth and has a weight twice that of lead per teaspoon.
- Osmium belongs to the platinum group and is hard in nature.
- The density of Osmium is 22.6 kg/L.
- Among the given options Lithium is the lightest metal and Osmium is the heaviest metal.

- So, the correct option is B.

Note: Because of its lightest nature of lithium it has significant uses in nuclear physics. Osmium has very few uses and it is used to produce hard alloys used in pen tips, and in electrical contacts. In chemical industries it is used as a catalyst.