Color Change
Chemical change
Example: Glow sticks "glow" when popped. Leaves turn from green to brown in the fall. Silver metal turns orange when it rusts.
Gas Production
Chemical change
We cannot see most gasses but we will often see bubbles and fizzing.
Example: When vinegar and baking soda is mixed you observe bubbles/fizzing. Be careful, some bubbles are the result of physical changes like blowing a bubble when chewing
Precipitate Formation
Chemical change
Example: Two liquids combined will react and create a solid. (Think about the example from our lab in class)
New substance is formed
Chemical change
ALL chemical changes form a new substance. For example: If you burn wood, ash is made. When oxygen reacts with metal, rust is made.
Change in smell or odor
Chemical change
Example: When milk goes bad you might smell a foul odor.
Change in temperature
Chemical change
Example: Hand warmers react and the temperature increases. In our class lab we mixed the white beads with water and the bag became warm.
Change in size, shape, or state.
Physical Change
Example: Ice melting, slicing bread, blowing a bubble with gum. No new substance is created.
a change that produces a new substance with different properties
Chemical Change
a change that causes a property to be different, but the substance has not changed
Physical Change
oxidation
A chemical change in which a substance combines with oxygen, as when iron oxidizes, forming rust
tarnish
the lost of luster due to the reaction with gases in the air
Combustion
the process of burning
a change that results from the rearrangment of atoms
chemical change
a change that occurs, but the arrangement of atoms does NOT change
physical change
reactant
A chemical substance that is present at the start of a chemical reaction
product
a substance that forms in a chemical reaction