A solution is another name for
O a heterogeneous mixture
O a mixture of elements
O a mixture of two liquids
O a homogeneous mixture

A heterogenous mixture.

Explanation:

A solution is another name for a heterogenous mixture.

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.

the answers would be

the first one and the second one