Arsenic (As) has an atomic number of 33 that indicates, it has 33 protons in its nucleus and 33 electrons around the electron while it is uncharged.

Molecular weight of oxygen is 31.99 and atomic weight is 15.88 and its atomicity is approximately 2.

Electrons are easily released and transferred from one atom to another by friction-glass and silk, wax and wool, heat-generating voltage by collision of bumpy metals, chemical reactions-oxidation.

The combination of two nuclides is called isotones if they have same neutron number-N, but different proton number-Z. Example: Boron-12, Carbon-13.

Atomic nucleus consists of electrically positive protons and electrically neutral neutrons. These two forces are also called strong force.

The basic unit of matter is atom, around 100 picometers, which reacts with chemical.

Water is known to exist in three different states; as a solid, liquid or gas. 

Moisture, snow, and rain are all made of up of some form of water. Moisture in the air is comprised of vapor, a snowflake is an aggregate of many ice crystals, and rain is just liquid water.

A chemical change is a change of materials to form into another, different materials with different properties and one or more new substances are formed. Rusting of iron is a chemical change because a new substance iron oxide is formed. The presence of oxygen and water is essential for rusting. Rusting of iron is a continuous process that slowly eats up the iron objects and makes them useless.

Benzene is an organic chemical compound with the molecule. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal ring with one hydrogen atom attached to each other. As it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon.

Air is a mixture, not compound. There are multiple elements present in air but they do not react with each other to form a singular substance that can be called "air". Air can be broken down basically into 78% nitrogen, 22% oxygen, and residual other gases and substance.