Science Section review

What type of change is needed to break down a compound?

A chemical change is needed to break down compounds.

Compare the properties of metals and nonmetals.

A metal is an element that is shiny and conducts heat and electricity. Nonmetals are elements that conduct heat and electricity poorly.

What is a pure substance?

A pure substance is a sample of matter, either a single element or a single compound that has definite chemical and physical properties.

Definition for term compound.

A substance made of atoms with several elements joined by chemical bonds.

The element in a compound.

A. Join in a specific ratio according to their masses. B. Combine by reacting with one another. C. Can be separated by chemical changes.

Why is rust different from iron or oxygen that it is made of?

After chemistry reaction a compound with new property is produced. Color is one of new properties.

Element and pure substance in sentence.

An element is a pure substance that cannot be separated into simpler substances.

What is a metalloid?

Elements that have properties of both metals and nonlethal.

Your friend tells you that a shiny element has to be a metal. Do you agree?

No, because a shiny element can also be a metalloid. A metalloid has both properties of metals and nonmetals and is shiny.

A jar contains samples of the elements carbon and oxygen. Does the jar contain a compound?

Yes because a compound is made of same substances which in this scenario are carbon and oxygen. Both these substances are made of atoms and joined by chemical bonds.