Physical vs. Chemical Changes
what happens during a physical change?
no new substance is formed (shape, size, state changes)
what is a compound?
two or more elements chemically combined.
what is a solid?
what is a liquid?
what is a gas?
definite shape and volume
definite volume, takes shape of container
no definite shape or volume/fills space
how do you calculate density?
Density = Mass / Volume
what is an element?
pure substance made of one type of atom
what happens during a chemical change?
A new substance is formed.
read these chemical formulas.
H2O, CO2, NaCl and CH4
melting is ___ to ___ and freezing is ___ to ___.
solid to liquid - liquid to solid
what do high and low density objects do in water?
high density = sink
low density = float
what is filtration for.
separating solids from liquids
What is the difference between physical and chemical changes?
Chemical changes create a new substance but physical changes do not.
what is an atom?
The smallest unit of Matter.
what is evaporation?
liquid to gas
what is a mixture?
substances physically combined
what is magnetism for.
iron materials
what is evidence of a chemical change?
- color change
- gas production
- temperature change
- formation of a solid/precipitate
what is a molecule?
atoms bonded together.
what is condensation?
gas to liquid
what is a homogeneous mixture?
evenly mixed / cant see different particles
what is evaporation for?
separating dissolved solids like salt from water.
what are two examples of each type of change?
rusting and burning
melting and tearing
all matter ____ and ____.
has mass
takes up space (volume)
what is deposition?
gas to solid
what is a Heterogeneous mixture?
unevenly mixed (can see parts)
what is sieving for?
separating different sizes