The Atmosphere and UV

Question 1

Main gases in the atmosphere

Answer 1

Nitrogen
Oxygen
Argon
Carbon dioxide

Question 2

Earth suitability for life

Answer 2

Earth is the only known planet that has an atmosphere capable of sustaining life.

Question 3

Layers of the atmosphere

Answer 3

Troposphere, Stratosphere, Mesosphere, Thermosphere, Exosphere

Question 4

Troposphere

Answer 4

Layer closest to the Earth, containing approximately half of Earth’s atmosphere.
Almost all water and dust are found in this layer, forming clouds.
Where most of Earth’s weather is controlled and created.

Question 5

Stratosphere

Answer 5

The air in this layer is drier and less dense.
Aircrafts often fly in the lower stratosphere to escape the turbulence in the troposphere.

Question 6

Mesosphere

Answer 6

The layer that protects the Earth against meteors

Question 7

Thermosphere

Answer 7

Space shuttles and some satellites orbit the Earth within this layer.
A person travelling in this layer is considered an astronaut.
Auroras take place in this layer.

Question 8

Exosphere

Answer 8

The outermost and least dense atmospheric layer.
It has no definite outer limit as it merges with space.
Many satellites orbit the Earth within the exosphere.

Question 9

The ozone layer composition

Answer 9

Ozone is a pale blue gas made from three oxygen atoms, It absorbs most of the harmful ultraviolet radiation from the sun. Ozone is found throughout the troposphere and stratosphere, but at an altitude of approximately 20km, there is a higher ozone concentration in the air. This area of high concentration is referred to as the ozone layer.

Question 10

Thinning of the ozone layer

Answer 10

Thinning of the ozone layer (often referred to as a hole in the ozone layer) can result in changes to the Earth’s climate, in particular temperature.

Question 11

UV radiation

Answer 11

Ultra-violet radiation is part of the radiation emitted by the Sun

Question 12

Three types of UV rays

Answer 12

UV-A, UV-B, UV-C

Question 13

UV-C?

Answer 13

UV-C: the highest energy UV radiation and harmful to all living things, but is entirely screened out by oxygen (O2) and ozone (O3).

Question 14

UV-B

Answer 14

excessive exposure can cause cataracts, immune suppression, sunburn and skin cancer due to genetic damage.

Question 15

UV-A

Answer 15

ozone is transparent to this UV wavelength so it reaches the Earth. This type of UV is significantly less harmful to DNA but can indirectly cause skin cancer and premature skin ageing.

Question 16

What about UV rays compared to normal rays cause skin problems

Answer 16

Ultraviolet light has higher energy compared to visible light. It is this high energy component of sunlight that damages cells and tissues

Question 17

UV radiation on a cellular level

Answer 17

When UV radiation is absorbed by our cells, it causes electrons in cellular components to be excited.
This cause unwanted molecular breakdown and abnormal cellular activities.

Question 18

UV Radiation damage & repair

Answer 18

The human body has evolved to deal with UV damage, but if the damage outweighs the body’s ability to repair it, or the repair mechanism itself is damaged, then signs will start to appear.

Question 19

Sunburn

Answer 19

Just one bad sunburn can lead to long-lasting damage to the skin and increase the risk of skin cancer.

Question 20

Strategies to prevent skin damage

Answer 20

Avoid the sun during peak hours (10 am - 2 pm)
Seek shade
Wear clothing with a broad-spectrum, water-resistant UPF of 50+
Wear a wide-brimmed hat
Use sunscreen year around. Some of the worst burns occurred in the winter
Apply sunscreen 15 minutes before going outdoors. It takes 15 minutes to be absorbed by the skin