Which statement is true about the substances present in a mixture? They always consist of the same element.

They are always in the same state of matter.

They can be separated by physical methods.

They can only be separated by chemical methods.

They can be separated by physical methods

Explanation:

A mixture contains 2 or more substances which are occurring together. Although they are occurring together, it is important to note that they are not chemically bonded.

What we are trying to say is that there is no chemical bond between the substances present in a union.

They are particularly bonded physically. Hence, to separate a mixture into its constituent parts, we surely need to employ the use of a physical method that works to separate these substances into their different parts.

The physical method selected is based on the properties of the materials present in the mix

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.

b.

the accuracy of the data.