How many valence electrons does potassium have?

The speed of light is around 6.706×10^8 miles per hour. what is the speed of light in units of miles per minute?

The volume of a single vanadium atom is 9.29×10-24 cm3. what is the volume of a vanadium atom in microliters?

Which answer tells the reason the earth’s climate is getting warmer? too many animals are becoming extinct. large glaciers are melting in antarctica. the earth is moving closer to the sun. driving cars gives off gases that trap heat in the atmosphere.