matter is made of extremely small particles called?
atoms
the term "atom" comes from a Greek word that means?
"cannot be divided"
a small particle that makes up most types of matter
atom
pure substances that cannot be changed into simpler substances
elements
elements are composed of how many kinds of atoms?
one
elements can be combined to form?
compounds
mixtures
pure substances that are composed of 2 or more types of elements that are chemically combined
compounds
compounds can only be changed into simpler substances called ___ by chemical changes
elements
one way that 2 or more atoms can combine is to form?
a molecule
composed of 2 or more different substances that retain their own individual properties and are combined physically
mixtures
mixtures can be separated by?
physical means (filtration, sifting, or evaporation)
mixtures may be?
homogeneous
heterogeneous
mixture that is not uniform throughout and the component substances can be visibly distinguished
heterogeneous
mixture that is uniform throughout and the substances are evenly mixed and cannot be visibly distinguished - particles of the substances are so small that they cannot be easily seen
homogeneous
another name for homogeneous mixture
solution
how many types of elements are compounds composed of?
2 or more
how many different substances are mixtures composed of?