The percentage composition of oxygen in air is

Which of the following best describes global warming? The current temperatures on Earth - The weather during the summer - The increase in the average temperatures on Earth

What greenhouse gas is released into the atmosphere from gasoline-burning cars? Carbon dioxide - Water vapor - Ozone - Oxygen

Air is considered to be ? element - compound -mixture - a solvent

Global warming is caused by a phenomenon known as the greenhouse effect. (true-false)

Which gas does not support burning? Oxygen - Hydrogen -Carbon dioxide -Nitrogen

Which of the following gas is used for breathing?

The main human activity that releases greenhouse gases is using bottled water -burning fossil fuels - texting on cellphones - eating meat

Oxygen is important on earth because it is essential for the life of

The composition of nitrogen gas in the atmosphere is