How do alkali metals differ from alkaline earth metals

Alkali metals and alkaline-earth metals are similar, but they are different in some ways as well. Alkaline-earth metals are slightly less reactive that alkali metals and more dense. Alkali metals have a very low density so they can be cut fairly easily. Both of these metals have a silver color.

space exploration has led to the development and technological improvement of many everyday items. (if this answer is wrong i will find the right answer) : )

what is the average time it took the car to travel 0.25 meters?

⇒ 2.23 seconds

what is the average time it took the car to travel 0.50 meters?

⇒ 3.13 seconds