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

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

The composition of nitrogen gas in the atmosphere is

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

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

Which of the following gas is used for breathing?

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

The percentage composition of oxygen in air is

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

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