The statement which describes a physical property of the element oxygen is

1. oxygen is needed for the rusting of iron
2. oxygen supports the burning of paper
3. oxygen has a density of 1.43 grams per liter
4. oxygen must be present for food to decay

What happens when light is scattered?

Which of the following units is not an official si unit

In chemistry, the type of an atom (what element it is) is determined by: a) the number of protons it contains in its nucleus.b) the number of neutrons it contains in its nucleus.c) the number of protons it has in a cloud around the nucleus.d) the number of neutrons it has in a cloud around the nucleus.e) the number of electrons it exchanges with its neighbors.