The air created the mold and spread it
D, light can travel in the air or a vacuum and the speed is constant whether the light source is stationary or moving.
Answer:
Volume= 4 cm³
Density= 2 g/cm³
Explanation:
We have the following data:
volume= V= 8 cm³
mass= m= 16 g
The density is the mass per volume of a substance, so the density of the rock is:
density= d= 16 g/8 cm³= 2 g/cm³
When we cut the rock in half, we have a half volume and a half mass:
V= 8 cm³/2= 4 cm³
m= 16 g/2= 8 g
But the density is not altered because it is an intrisic property - it does not change with the amount of subtance. Thus, the density of a half rock is:
d = m/V= 8 g/4 cm³= 2 g/cm³
More than 99 percent of all species, amounting to over five billion species, that ever lived on Earth are estimated to be extinct. Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described.
