A(n)
has different properties than the elements that
compose it and is made of substances combined in a specific ratio.

A compound

Explanation: A compound is a substance that is made up of two or more elements that are combined chemically and can be separated only by chemical means.

The properties of a compound differ from the properties of its constituent elements. For instance carbon dioxide (CO2) is made up of carbon and oxygen atoms. The properties of carbon dioxide is different from the individual properties of carbon and oxygen.

Compound are made up of elements that are combined in a specific ratio. The ratio of carbon to oxygen in Carbon dioxide is 1 : 2. This means that there are one carbon atom (C) and two oxygen atoms (O2) in one molecule of carbon dioxide (CO2).

gas

explanation:

smoke is the matter of a gas

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.