elements compounds and mixtures Flashcards
what are substances that are only made up of one type of atoms
elements
what are compounds
a pure chemical substance formed when two or more elements are chemically combined in a fixed ratio to form a new product (eg water, salt, sugar)
how can compounds be broken down/broken apart
by heating or chemical reaction
true/false
when different elements are chemically combined to form a compound, the compound has properties that are different from the elements it is formed from.
true
how many elements is this made from
NaCl
2
how many molecules does this chemical have
CuCO₃
1
one C atom and three CO atoms are chemically combined to from a single CuCO₃ molecule
true/false
all compounds have a definite composition
true
what is a mixture
a mixture contains two or more components that are mixed together in any proportion
how to separate a mixture
can be separated by physical means (eg filtration, distillation)
true/false
mixtures have a sharp melting and boiling point
false
a mixture is impure, so it will melt or boil over a range of temperatures unlike a pure substance
true/false
both mixtures and compounds have a new set of properties different from its elements
false
a mixture shows the properties of its components but a compound has a new set of properties different from its elements
what energy changes when chemical reactions take place for compounds
heat and light energy
does the elements react chemically for mixtures
no, thus no energy changes take place
what elements are brass made out of
copper and zinc
what are the three main types of mixtures
- element and another element
- element and compound
- compound and another compound
