69 terms

5th grade science chemical and physical changes

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matter changes in size, shape or state without changing identity
physical change
chemical changes occur when what links together in new ways
atoms
a change in matter that produces a new compound with different properties from the original
chemical change
Chemical change
Chemical changes are ___________ to reverse
difficult
when iron atoms in steel react with oxygen the chemical change that occurs is called rust or ___________
iron oxide
one of the original substances before a chemical change
Reactant
New substance produced by a chemical reaction is called
Product
Physical changes can sometimes be easily ____
REVERSED
in a chemical change, a sign that gas is being released might appear as __________
bubbles
when baking soda and water are mixed the baking soda seems to disappear, however we can get it back when the water ______
evaporates
when you light a match, one of the signs of a chemical reaction is that is gives off ______
heat
the gas that is released when a cake is baked
carbon dioxide
water changing from a liquid to a solid is called a change of ____
state
mold and ________ can cause chemical reactions in food
bacteria
chemical reactions in food slow down when the temperature is
lowered
mold growing on food is an example of a _________
chemical reaction
burning candle is an example of __________
physical and chemical change
Physical changes are changes in a substances
form, state, appearance
The changes that formed the Grand Canyon were ______changes
physical changes
An example of a chemical change that happens inside your body
food broken down by ENZYMES in your stomach
An example of a physical change that happens inside your body
Food being broken down into small pieces by your teeth
a change at the molecular level
chemical change
matter changes size, shape and form
physical change
reactant + reactant = ?
product
4 signs that mean a physical change may have occurred
change of size, change of shape ,change of state, change of color
Physical changes do not change the _____ of the substance
identity
4 signs that mean a chemical change may have occurred
formation of heat, formation of light, formation of gas, formation of color (tarnish)
chemical changes occur when ____ link together in new ways and form new _______
atoms substances
formation of rust (chemical or physical change)
chemical
inflating a balloon (chemical or physical change)
physical
molding clay into a statue (chemical or physical change)
physical
burning toast (chemical or physical change)
chemical
baking a cake (chemical or physical change)
chemical
melting an ice cube (chemical or physical change)
physical
fireworks (chemical or physical change)
chemical
burning a candle (chemical or physical change)
both
cutting paper (chemical or physical change)
physical
lighting a match (chemical or physical change)
chemical
cutting your hair (chemical or physical change)
physical
milk souring (chemical or physical change)
chemical
breaking glass (chemical or physical change)
physical
boiling water (chemical or physical change)
physical
snowman melting (chemical or physical change)
physical
painting a picture (chemical or physical change)
physical
banana ripening (chemical or physical change)
chemical
dissolving salt in water (chemical or physical change)
physical
moldy cheese (chemical or physical change)
chemical
what happens to the total number of atoms of each substance before and after a chemical reaction
The atoms stay exactly the same
chemical change that happens when silver reacts with sulfur is called
tarnish
when food is cooked thoroughly it causes the microorganisms to _______
die
milk, fish and diary products should be _______ immediately
refrigerated
when milk is heated to high temperatures to kill microorganisms, it's called
pasteurization
food that is past its expiration date should be ____
thrown away
forms a totally new substance (chemical or physical change)
chemical
keeps its properties (chemical or physical change)
physical
a simple change in size (chemical or physical change)
physical
formation of gas (chemical or physical change)
chemical
new product has different properties (chemical or physical change)
chemical
color change that can be explained (chemical or physical change)
physical
difficult to reverse (chemical or physical change)
chemical
a simple change of shape (chemical or physical change)
physical
sound may be given off (chemical or physical change)
chemical
unexplainable color change (chemical or physical change)
chemical
atoms do not change (chemical or physical change)
physical
temperature changes (chemical or physical change)
chemical
bubbles (chemical or physical change)
chemical
gives off an odor (chemical or physical change)
chemical
sometimes easy to reverse (chemical or physical change)
physical
no new substance created (chemical or physical change)
physical