Chemical Change Definition in Chemistry (questions on article)
When food rots, its appearance changes has visible changes. This is _______.
change in composition
A ____________is a chemical reaction involving the rearrangement of the atoms
chemical change
Any chemical reaction is an example of a ________.
chemical change
One that absorbs heat is called an _____ _____ and it is ______.
endothermic reaction, cooler
A chemical change that gives off heat is called an _____ ____ and it is ________.
exothermic reaction, warm
Examples of chemical reactions- digesting _______.
food
An example of a physical change that is not an chemical change is: breaking a _______, cracking open an _____ and mixing sand with _____.
glass, egg, water
Examples of chemical reactions- adding heat to _____ and _____ (produces water)
hydrogen, oxygen
Some reactions that produce _____.
light
Most chemical changes are _____ ____, except via another reaction.
not reversible
A chemical change occurs when one substance is transformed into _____ or ____ new products via a ____ _____.
one or more, chemical reaction
Any change that does not form new products is a _________ _______ rather than a chemical change.
physical change
While a ______ _____ can often be reversed, a __________ ______ typically cannot be, except through more chemical reactions.
physical change, chemical change.
Some chemical reactions produce solid particles that may remain suspended in a solution or fall out as ______.
precipitate
Chemical changes are often difficult or impossible to ________.
reverse
A reaction may release a volatile chemical that proceeds a characteristic
scent (odor change)
Because there is an energy change in a chemical reaction, there is often a measurable _____ ____.
temperature change
Chemical changes may be identified by 8 items:
temperature change, light, bubbles, precipitate formation, color change, irreversible, change in composition
Examples of chemical reactions- combining baking soda and _______.
vinegar
Examples of chemical reactions- pouring peroxide on a _____.
wound
A ______ _____ is a good indicator that a chemical reaction has occurred.
Color Change
Some chemical changes _______ occur without any indication of change.
MAY
------ of iron produces heat and a color change, but it takes a long time for the change to be evident, even though the process is ongoing.
Rust
In a chemical change, the number and type of atoms stays constant, but their _______ is altered.
arrangement
When combustion occurs, _________ may be produced. This is _______.
ash, change in composition
Examples of chemical reactions- combining any acid with any_______.
base
Some chemical changes produce gasses, which can be seen as _____, in a liquid solution.
bubbles
Examples of chemical reactions- burning a _______.
candle
A ______ is thethe process by which one or more substances are alerted into one of more new and different substances.
chemical reaction
When a ________ change occurs, there is also a change in the ________ of the system.
chemical, energy
Reactions involving transition metals are particularly likely to produce______.
colors
Examples of chemical reactions- cooking an ______.
egg
