Questions

The first indicator of an approaching thunderstorm is a buildup of dark clouds.

A thunderstorm is a storm with lightning and thunder; it is usually produced by heavy rain, gusty wind, and the cumulonimbus cloud. The thunderstorm is made up of moisture, unstable air and lift.

Because arteries have to have thick walls for use of protection. Its when you get to veins where the walls get thinner. And the use of the heart is to pump blood to all of the cells and organs in the body so it would be to transport blood away from the heart.

i.e. 

Arteries = Away from the Heart 
Veins = Back to the Heart.

Most of the water in the body will be lost by kidneys in the form of urine.

In the periodic table, the atomic radius increases from top to bottom in the groups and it increases from right to left in the periods.

Francium is the atom with largest atomic radius. Helium is the atom with smallest radius.

15 May. Theme of International Day of Family 2017 is “Families, education and well-being”.