Explanation:
It is given that,
The time period of artificial satellite in a circular orbit of radius R is T. The relation between the time period and the radius is given by :

The radius of the orbit in which time period is 8T is R'. So, the relation is given by :



So, the radius of the orbit in which time period is 8T is 4R. Hence, this is the required solution.
Explanation:
Mg+O>MgO
Here the mg loses it electron and is oxidised and oxygen gains and is reduced.
Mg(2+)and O(2-)
Mg is a reducing agent it makes oxygen to be reduced while itself being oxidised and vice versa.
They discovered that *elements* show increase in atomic numbers across the period.
I cannot see your question to help you... sorry
The variable would be the distance you dropped them.