Explanation

The most abundant naturally occurring gas is nitrogen (N2), which makes up about 78% of air.

Oxygen (O2) is the second most abundant gas at about 21%.

The inert gas argon (Ar) is the third most abundant gas at 0.93%.

Explanation

The most available form of solid fuel is wood. Wood is obtained from the trees and when trees die and decomposed for years through is called coal.

Explanation

Sound travels at different speeds depending on what it is traveling through. Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids.

Temperature also affects the speed of sound.

Explanation

 The subject matter of physics includes mechanics, heat, light and other radiation, sound, electricity, magnetism, and the structure of atoms."

Explanation

Dry air from Earth's atmosphere contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and traces of hydrogen, helium, and other "noble" gases (by volume), but generally a variable amount of water vapor is also present, on average about 1% at sea level.

Explanation

Oxygen is the chemical element with the symbol O and atomic number 8. 

Explanation

A fluorescent lamp consists of a glass tube filled with a mixture of argon and mercury vapour.

Explanation

The ozone layer is a thin part of the Earth's atmosphere that absorbs almost all of the sun's harmful ultraviolet light. "Ozone holes" are popular names for areas of damage to the ozone layer.

Explanation

Biodiesel is a form of diesel fuel derived from plants or animals and consisting of long-chain fatty acid esters. 

Explanation

A beta particle, also called beta ray or beta radiation (symbol β), is a high-energy, high-speed electrons emitted by the radioactive decay of an atomic nucleus during the process of beta decay.