1 Produce a time line for the formation of the atmosphere, starting with the formation of the Earth 4500 million years ago.
2 Use your research skills to find out:
a more about the ozone hole problem
b what precautions are necessary to prevent an increase in
skin cancers.

Pls help

1) Well I think you need to research that in G00GLE

Explanation:

2 answer

a) The thinning is most pronounced in the polar regions, especially over Antarctica. Ozone depletion is a major environmental problem because it increases the amount of ultraviolet (UV) radiation that reaches Earth's surface, which increases the rate of skin cancer, eye cataracts, and genetic and immune system damage.

b) Seek the shade, especially between 10 AM and 4 PM.

Don't get sunburned.

Avoid tanning, and never use UV tanning beds.

Cover up with clothing, including a broad-brimmed hat and UV-blocking sunglasses.

Use a broad-spectrum (UVA/UVB) sunscreen with an SPF of 15 or higher every day.

a electronegativity decreases beacuse the size of nucleus is bigger.