Gases in the Atmosphere Flashcards

All 6 cards in this deck

Approximately what percentage of today's atmosphere is nitrogen?

About 80% (approximately four-fifths).

Approximately what percentage of today's atmosphere is oxygen?

About 20% (approximately one-fifth).

Name three gases present in small proportions in today's atmosphere.

Carbon dioxide, water vapour and noble gases.

For roughly how long have the proportions of gases in the atmosphere been much the same as today?

For about 200 million years.

True or false? Oxygen is the most abundant gas in today's atmosphere.

False. Nitrogen is the most abundant, at about 80%; oxygen is about 20%.

What are the steps to work out the percentage of a gas in a sample of air?
e.g. 50 cm$^3$ of a 250 cm$^3$ air sample is oxygen

1. Divide the volume of the gas by the total volume: $50 \div 250 = 0.2$
2. Multiply by 100: $0.2 \times 100 = 20\%$ oxygen