Question

this type of substance can be either homogeneous or heterogeneous.
mixture
compound
element
atom
question 7
when a substances appearance changes but the substances identity remains the same, it is called a select change.
select
chemical
physical
question 8
when there is all of same kind of substance (i.e. same characteristic properties and same composition), it is known as a...

Explanation:

First Question (Substance Type)

A mixture is a combination of two or more substances where each substance retains its own properties. Mixtures can be homogeneous (uniform composition, like saltwater) or heterogeneous (non - uniform composition, like a salad). Compounds are pure substances made of two or more elements chemically combined in a fixed ratio and have a uniform composition. Elements are pure substances made of only one type of atom. Atoms are the basic building blocks of matter. So the substance that can be either homogeneous or heterogeneous is a mixture.

A physical change is a change in which the form or appearance of a substance changes, but the chemical identity of the substance remains the same. For example, melting ice (solid water to liquid water) is a physical change as the substance is still water. A chemical change involves a change in the chemical identity of the substance, forming new substances (like burning wood, which forms ash, carbon dioxide, etc.). So when a substance's appearance changes but its identity remains the same, it is a physical change.

Answer:

mixture

Question 7 (Type of Change)