Classification of Matter
Classes of Matter
Matter is classified
according to makeup as elements, compounds, mixtures, or solutions.
Homogeneous matter has identical properties throughout.
Heterogeneous
matter has different properties throughout.
Mixtures
A mixture is composed of two or more substances
mixed together but not chemically combined.
The substances tha make up a mixture keep their separate identities and most of their own
properties.
The substances in a mixture can be present in any amount.
The substances in a mixture can be separated by simple
physical means.
A mixture that does not appear to be the same throughout is a heterogeneous mixture.
A mixture that
appears to be the same throughout is a homogeneous mixture.
A solution is a type of homogeneous mixture formed
whrn one substance dissolves in another.
The particles in a solution are not large enough to be seen, so most solutions are difficult
to separate.
Alloys are metal solutions in which solids are dissolved in solids.
Elements
A pure substance is homogeneous
matter. It is made of only one kind of material.
Elements are the simplest type of pure substances.
Elements are made
of atoms, which are the building blocks of matter.
Elements are representd by chemical symbols.
Compounds
Compounds are
two or more elements chemially chombined.
Compounds can be broken down into simpler substances.
Most compounds are mode of molecules. A molecule is made of two or more atoms chemically
bonded together.
A molecule is the smallest particle of a compound that has all the properties of that compound.
A chemical formula,
which is a combination of chemical symbols, usually represents a molecule of a compound.
A subscript give the nubmer
of atoms of the element in the compound.
A chemical equation describes a chemical reaction.
