Uses of the noble gases

The noble gases are unreactive or inert, which makes them safe to use. They also glow when a current is passed through them at low pressure. These properties lead to many uses:

• Helium is used to fill balloons and airships, because it is much lighter than air – and will not catch fire.
• Argon is used to provide an inert atmosphere. For example it is used: as filler in tungsten light bulbs and to protect metals that are being welded.
• Neon is used in advertising signs. It glows red, but the colour can be changed by mixing it with other gases.
• Krypton is used in lasers – for example for eye surgery – and in car headlamps.
• Xenon gives a light like bright daylight, but with a blue tinge. It is used in lighthouse lamps, lights for hospital operating rooms, and car headlamps.

Discuss the advantages and disadvantages of aspirin as a medicine

Advantages

• It is used to relieve pain such as arthritic pain, dental pain, etc where there is an inflammation involved.
• It is used to prevent thickening of blood and heart attack.

Disadvantages

• It is acidic and can cause internal bleeding and ulceration in the stomach. 

Explain the reactivity of halogens decreases when going down Group 17.

The atomic size of halogen increases when going down Group 17. Thus, the outermost occupied shell becomes further away from the nucleus. Hence, the strength of the nucleus to pull another electron into the outermost occupied shell becomes weaker. Thus, halogens are less reactive when going down Group 17. 

Explain how the melting and boiling points change when going down the Group 1.

Melting and boiling points of alkali metals decreases when going down Group 1. The atomic size of alkali metals becomes bigger when going down the group 1. Hence, the forces between alkali metal atoms are weaker when going down Group 1. Hence, less heat energy is required to break the weaker forces.

Why noble gases chemically inert?

Helium has a duplet electron arrangement whereas other noble gases have octet electron arrangements. These electrons arrangements are very stable. Hence, atoms of noble gases do not release electrons, accept electrons or share electrons with other atoms. Thus, they are chemically inert. 

Why is neon exists as a monoatomic gas?

• Neon is from the Noble Gases group on the periodic table. 
• Neon has electron arrangement is 2.8 (valence electron is 8). 
• Neon already achieves the octet electron arrangement. 
• Neon does not need to donate the electron with other element. 
• Therefore they do not gain or lose electrons making them exist as individual atoms. 
• Neon exists as a monoatomic gas. 

Kinetic Molecular Theory

• Matter consists of small particles that always move and collide among each other.
• The kinetic theory of matter stated the particles move freely when energy is absorb and move slowly when energy is release, then they are cooled.
• The kinetic molecular theory used to explain the change physical state of matter.
• Gas molecules are individual particles that travel in a straight-line random motion. This will continue until they collide or are acted upon by another force.
• Gas molecules continuously collide and transfer energy during these collisions. In an isolated sample of gas the net energy is conserved.
• The volume of the individual gas molecules is negligible compared to the volume they occupy.
• No forces of attraction are considered to exist between the gas molecules.