Answer:
Nitrogen
Step-by-step explanation:
The Earth’s atmosphere is primarily consists of gases and rare elements.
99% of atmosphere is composed of gases like oxygen and nitrogen. The percentage composition of earth’s atmosphere is - Nitrogen — 78 percent, Oxygen — 21 percent, Argon — 0.93 percent, Carbon dioxide — 0.04 percent also there are several rare elements such as helium, methane, argon, hydrogen, water vapour , etc.
Thus, it can be said that 99% of atmosphere is made up of oxygen and nitrogen.