Classify each of the following statements as either an observation, a hypothesis, an experiment, or a scientific law. 1. A candle decreases in mass after burning.

2. The mass decreases because gases are being released from the candle as it burns.

3. Limewater is used to test for the presence of carbon dioxide gas as a candle is burned.

4. For any chemical process, mass cannot be created or destroyed, only rearranged

Which of the following is a compound? a.carbon b.oxygen c.hydrogen d.water

If we compare and contrast electromagnetic waves with sound waves, all but one statement is true. that is a) sound waves require a medium to travel while electromagnetic waves do not. b) electromagnetic waves can travel through the vacuum of space while sound waves cannot. c) electromagnetic waves must have a medium in which to travel, but sound waves can travel anywhere. eliminate d) sound waves must bounce off of matter in order to travel while electromagnetic waves do not require matter to be present.

Adeuteron, 21h, is the nucleus of a hydrogen isotope and consists of one proton and one neutron. the plasma of deuterons in a nuclear fusion reactor must be heated to about 3.02×108 k . what is the rms speed of the deuterons? express your answer using two significant figures.