Chemical reaction
white spots caused by the bleach
color change
About how many elements make up all known substances?
100
How many atoms make up a diatomic molecule?
2
What is the relationship between a chemical reaction and the making and breaking of chemical bonds?
In a chemical reaction, the bonds between atoms in molecules break, the atoms rearrange, and new chemical bonds form. The new arrangement of atoms produces new substances.
How do the properties of the new substances compare with the properties of the original substances after a chemical change takes place?
They may differ in chemical and physical properties.
A process in which one or more substances change to form new substances is called a
chemical reaction
Which of the following names the process by which chlorophyll breaks down into new substances?
chemical reaction
thermal energy produced by a fire
energy change
What is the most important sign that a chemical reaction is occurring?
formation of new substances that have different properties
bubbles
gas formation
What is a chemical bond?
is a force that holds two atoms together in a molecule
When a gas is given off as a liquid boils, it is an example of a _____ change, not a _______ reaction.
physical;chemical
A solid substance that is formed in a solution is called a
precipitate
precipitate
solid formation
