2. 1. Small talk about oxygen 2. chemical properties 3
1.Small talk about oxygen 2.chemical properties 3.physical properties 4.discovers

8. Air fit that description, along with fire, water, and earth.
SYMBOL 0
ATOMIC NUMBER 8
ATOMIC MASS
FAMILY Group 16 (VIA) Chalcogen
Oxygen is necessary for the survival of all animal life on Earth. Animals breathe in oxygen and breathe out carbon dioxide. One important use of oxygen is in medicine. People who have trouble breathing are given extra doses of oxygen. In many cases, this "extra oxygen" keeps people alive after they would otherwise have died But oxygen has many commercial uses also. The most important use is in the manufacture of metals.

9. Chemical properties
Oxygen's most important chemical property is that it supports combustion. That is, it helps other objects to burn. The combustion (burning) of charcoal is an example. Charcoal is nearly pure carbon (C):
Oxygen also combines with elements at room temperature. Rusting is an example. Rusting is a process by which a metal combines with oxygen. When iron rusts, it combines with oxygen:
Oxygen also reacts with many compounds. Decay is an example. Decay is the process by which once-living material combines with oxygen. The products of decay are mainly carbon dioxide (CO 2 ) and water (H 2 O): (The chemical formula for "dead matter" is too complicated to use here.)
Oxygen itself does not burn. A lighted match in a container of pure oxygen burns much brighter, but the oxygen does not catch fire.

10. Physical properties
First, they differ on the simplest level of atoms and molecules. The oxygen that we are most familiar with in the atmosphere has two atoms in every molecule. Chemists show this by writing the formula as O 2 . The small "2" means "two atoms per molecule."
That is, dioxygen is the normal condition of oxygen at room temperature.
The third allotrope of oxygen, ozone, has three atoms in each molecule. The chemical formula is O 3 . Like nascent oxygen, ozone does not exist for very long under normal conditions. It tends to break down and form dioxygen: