Which gas was thought to be a major part of the early atmosphere?
Carbon dioxide
Nitrogen
Oxygen
Which of these planets has an atmosphere most similar to what scientists thought the Earth's early atmosphere was like?
Mercury
Venus
Saturn
In the modern day atmosphere, what is the approximate percentage of nitrogen?
0.04%
20%
80%
What biochemical process absorbs carbon dioxide from the atmosphere and replaces it with oxygen?
Respiration
Digestion
Photosynthesis
Which process removed carbon dioxide from the atmosphere?
Formation of igneous rocks
Formation of sedimentary rocks
Formation of metamorphic rocks
Which gas produced by the combustion of fossil fuels causes acid rain?
Sulfur dioxide
Ozone
What is the laboratory test for oxygen?
Puts out a glowing splint
Makes a squeaky pop sound with a burning splint
Relights a glowing splint
Which two main processes take place naturally and, when combined, help to keep the level of oxygen in our atmosphere nearly constant?
Respiration and combustion
Photosynthesis and combustion
Respiration and photosynthesis
Acid rain is caused by the reaction of rain water with which pollutant gas?
Argon
Which test can be used to positively identify carbon dioxide gas?
Put the flame of a burning splint into the test tube full of carbon dioxide – the flame will be extinguished
Bubble the carbon dioxide through limewater – the limewater will change colour from clear colourless to milky white
Put the glowing end of a recently extinguished splint into a test tube full of carbon dioxide – the splint will re-ignite