All matter can be classified as either a substance or mixture. A substance is an element or a compound. A mixture is heterogeneous or homogeneous….

A heterogeneous mixture varies in its composition. Mixtures can be classified on the basis of particle size into three different types: solutions, suspensions, and colloids. The components of a mixture retain their own physical properties.

Answer: A mixture is a combination of two or more substances (elements or compounds) which is not done chemically. Mixtures are two types Homogeneous Mixtures and Heterogeneous mixtures. Homogeneous Mixtures: A Homogeneous mixture has a uniform composition of its components throughout its mass.

Elements are those pure substances that cannot be decomposed by ordinary chemical means such as heating, electrolysis, or reaction. Gold, silver, and oxygen are examples of elements. Compounds are pure substances formed by the combination of elements; they can be decomposed by ordinary chemical means.

(1) Ammonia is composed of one nitrogen and three hydrogen atoms so it is a compound. Therefore it can be broken down by chemical change.

C and Cu cannot be broken down by chemical change.

Which substance CAN be broken down by chemical means? Compound because the atoms of the elements are combined in a fixed proportion.

Any substance that contains only one kind of an atom is known as an element. Because atoms cannot be created or destroyed in a chemical reaction, elements such as phosphorus (P4) or sulfur (S8) cannot be broken down into simpler substances by these reactions.

Typically, the identity of a substance can be described by a:

1. chemical name, for example, benzene;
2. number, for example, EC number 200-753-7, and.
3. chemical composition, for example, >99 % benzene and <1 % toluene. The composition is determined by chemical analysis.