Question

What is one element which is a gas at room temperature and in which the atoms are joined together in a molecule?

Answer 1

Hint: There are basically three states of matter which are known as solid, liquid or gas. Where matter can be defined as anything that occupies space and has some mass. These three states of matter can be distinguished on different basis.

Complete answer:
In chemistry an element can be defined as the pure substances which consist of atoms which have the same number of protons in their atomic nucleus. Where protons are positively charged in nature.
Elements are those which cannot be broken down into further components. When different elements undergo different chemical reactions then atoms are rearranged into new compounds which hold together with the help of chemical bonds.
The element which is gas at room temperature is oxygen gas and this is the only element which when combined with itself it remains gas at room temperature. Oxygen is represented by the symbol $O$ whereas it is present in the form of gas when it reacts with itself and represented by the chemical formula $O_2$. Hence oxygen is very reactive in nature and joined together to form the gas.
Hence oxygen is the element which is gas at room temperature and in this the atoms are joined together in a molecule.

Note:
Oxygen gas is very important for human beings as the gas we inhale for living is oxygen gas there is no life possible without oxygen and the main source of oxygen is the process done by plants known as photosynthesis.