What makes a pure substance different from a heterogeneous mixture? a.) the components of a pure substance are mixed unevenly instead of evenly within the pure substance. b.) insoluble instead of soluble particles are suspended within the pure substance. c.) two liquids that normally are not mixable are mixed in a heterogeneous mixture. d.) the components of a pure substance are single elements or compounds instead of a mixture of compounds.

D.) The components of a pure substance are single elements or compounds instead of a mixture of compounds.

Explanation:

A pure substance is made up of the same type of atoms. An example of a pure substance is an element, which is made up of the same atoms. Gold element is made up of all gold atoms.  

A heterogeneous mixture contains two or more components and each component may or may not be in a different phase. Such in a bowl of salad the lettuce is solid and the dressing is a liquid, so a salad is a heterogeneous mixture.  

c. 4.54 x 10–12 j happens to be correct