Apparatus used to investigate whether oxygen is used during aerobic respiration Questions 1. Identify the experiment and the control. Explain your answer. (2) 2. What precaution do you need to take before setting up the experiment? (2) 3. What is the function of the soda lime in the test tube? Explain why this is necessary. • As the beetle respires and uses the gas in the test tube what happens: a) to the volume of the gas in the test tube? (1) b) to the coloured water in the rubber tubing? Why is the test tube kept in water at a constant temperature? (2) What temperature should the water be? Give a reason for your answer. (2) Why is oxygen necessary during aerobic respiration? (2)

✿   this landform has a high elevation and a high relief

✿   this landform is a mountain

oxygen is the first element in group 16 (via) of the periodic table. the periodic table is a chart that shows how chemical elements are related to each other. the elements in group 16 are said to belong to the chalcogen family. other elements in this group include  sulfur, selenium, tellurium,  and  polonium.  the name chalcogen comes from the greek word  chalkos,  meaning "ore." the first two members of the family, oxygen and sulfur, are found in most ores.

oxygen is by far the most abundant element in the earth's crust. nearly half of all the atoms in the earth are oxygen atoms. oxygen also makes up about one-fifth of the earth's atmosphere. nearly 90 percent of the weight of the oceans is due to oxygen. in addition, oxygen is thought to be the third most abundant element in the universe and in the solar system.