Vocab
made up of different kinds of atoms that are chemically combined
compound
How many atoms and elements are in CO2?
3 atoms and 2 elements
composed of two or more elements not chemically combined
what is a mixture
salad
mixture
are mixtures pure substances
made of only one kind of atom
element
Why can a magnet be used to separate a mixture of rubber and iron nails ?
The iron nails will are magnetic and will be attracted to the magnet.
can mixtures be separated chemically or physically
mixtures can be separated physically
ammonia
compound
what two things are considered pure substances
elements and compounds
the smallest unit of an element that maintains the properties of that element
atom
A substance has a pH of 3. To which class of compounds does it belong?
Acids
what are the two groups mixtures are separated into
homogeneous and heterogeneous
oxygen
element
what is the difference from a pure substance and a non pure substance
pure substances cant be separated physically
mixture has the same composition throughout
homegenous
What kind of mixture is oil and vinegar?
it is an example of a heterogeneous mixture because we can easily see small particles in the salad dressing
another word for homogeneous
solutions
salt
compound
give one example of a pure substance
salt, neon, anything that is an element or compound
mixture is one that does not have a uniform composition
heterogenous
What happens when a pure substance undergoes a chemical change?
When a pure substance undergoes a chemical change, it is no longer that same substance.
two types of heterogeneous mixtures
suspensions and colloids
gold
element
describe pure substances
pure substances are substances that are chemically combined