Simon has collected three samples from the coral reef where he observes marine life. he must determine whether each one is a pure substance or a mixture. sample a : clear liquid. evaporates at 70*c. appearance does not change. sample b : clear, blue liquid. boils at 90*c leaving blue crystals behind. appearance does not change. sample c : opaque, whitish liquid. boils at 100*c leaving white crystals behind. dust appears to settle at bottom. answer choices for each one are - homogeneous mixture, heterogeneous mixture, or pure substance

Sample A is a pure substance, Sample B  is a homogeneous mixture and Sample C is a heterogeneous mixture.

Explanation:

Homogeneous mixture : In these mixture, all the component are uniformly distributed throughout the mixture.For example: sugar-water solution.

Heterogeneous mixture : In these mixture, all the component are not uniformly distributed throughout the mixture.For example: sand-water solution.

Pure substance : These are the substance made up only one type of atom or molecule.They have fixed value of boiling and melting points. For example: diamond, pure sugar etc.

Sample A is a clear liquid which evaporates at with no change in appearance. Hence, pure substance.

Sample B is a clear blue liquid which boils at and leaves blue crystals behind with change in appearance. Hence, homogeneous mixture

Sample C is a opaque, whitish liquid which boils at and leaves white crystals behind with dust particles settled in the bottom. Hence, heterogeneous mixture.

1.solid

2.carbon dioxide

3.helium

the answer is na (sodium)