Potassium or any other metals.
Answer/Explanation:
We cannot see the passage, but SAD stands for Seasonal Affective Disorder. SAD is a type of depressive disorder related to lack of light, and therefore changes with the seasons. It is a severe version of the "winter blues"
In the winter months, where the days are shorter, individuals who suffer from SAD suffer from mood changes. They get depressed, have a reduction in energy levels, and withdraw socially. They may also gain weight. This causes problems with relationships, work, and school.
Since SAD is linked to light, SAD is likely more common in the Northern areas of the United States, where winter days are shorter.
Answer:10,0000 years
Explanation:
If it takes 2000 years to weather 1cm of limestone
It will take 5*2000 years to weather 5cm of limestone. This gives us 10000 years.
Answer:
Rubidium
Explanation:
Rubidium is an alkali metal that has 37 protons 48 neutrons and 1 valence electron