Argon

Argon is a chemical element with the symbol Ar and atomic number 18. It is in group 18 of the periodic table, making it a noble gas. Argon is the third-most abundant gas in the Earth's atmosphere, making up about 0.93% of the air we breathe. It is colorless, odorless, and non-reactive under normal conditions, making it useful in a variety of applications.

Properties of Argon

Argon is a noble gas, which means it is inert and does not readily form chemical compounds. Some of its key properties include:

Atomic number: 18
Atomic mass: 39.948
Phase at room temperature: Gas
Boiling point: -185.7°C
Melting point: -189.3°C
Density: 1.784 g/L

Uses of Argon

Argon has several important industrial and scientific applications, including:

As a shielding gas in welding and metalworking processes
In the production of high-quality glass and as a protective atmosphere in the manufacturing of semiconductors
In gas-discharge lighting, such as fluorescent and neon lights
As a preservative gas for protecting materials that are sensitive to oxygen and moisture
In laboratories for various analytical and scientific purposes

Study Guide

Here are some key points to remember about argon:

Argon is a noble gas with the symbol Ar and atomic number 18.
It is the third-most abundant gas in the Earth's atmosphere.
Argon is colorless, odorless, and non-reactive under normal conditions.
Its uses include welding, manufacturing, lighting, and scientific research.
Argon is an important component in various industrial and scientific processes due to its inert and non-reactive nature.

Remember to review the properties and uses of argon, as well as its place in the periodic table, to fully understand its significance in the world of chemistry and industry.