Exploring the Chemical World, PGCC, 2003
Here are some important things to remember or refer to as you do this activity:
Chemical changes are rearrangements of atoms.
New substances with different properties are
All formulas for reactants and products must
Matter is neither created nor destroyed during chemical or physical changes.
All atoms must be
an equation means making the number of atoms of a particular
element equal on both sides of the equation.
never change a subscript
You add or change numbers in front of substances to achieve the equality.
added values are called
The diatomic elements (hydrogen, oxygen, nitrogen, fluorine, chlorine, bromine, iodine) must be
written with a subscript of 2 when they are not combined with another element.
If one metal is more reactive than another metal (hydrogen included) it will replace the less
active metal in a compound.
Many reactions take place in solution, that is, the reactants are dissolved in water.
cases, one of the products is a gas or solid that does not dissolve in water.
When this occurs it
is easy to tell that a reaction has taken place because you can see bubbles or a solid
(cloudiness) appear suddenly.
The formation of a solid through a chemical reaction is called
In certain reactions, however, the product(s) dissolve instantly so that it is not