What mineral is the hardest known substance in nature?

The hardest known substance in nature is diamond.

Explanation:

It is rated a 10 on the Moh's hardness scale and it can only be cut by another diamond!

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.

colorless gas, exhibiting a blue glow when placed in an electric field

b) solid

its a type of rock