2. StaTes of Matter Changes
There are three basic states of
matter, solids, liquids, and gasses. When a physical change happens it
For them to be able to change does not change anything
states it requires energy in the chemically. Example would be
forms of heat and pressure. when water freezes, or boils.
When a chemical change happens it
These changes can be either changes the chemical composition.
intensive or extensive property. It looks different. Example would
Intensive properties do not depend be burning paper.
on the size and is the color or
density of the sample while
You can remember the
extensive properties do depend on
difference between them by a
the size of the sample because it
physical change is reversible,
deals with the mass and volume.
while chemical is not.
3. Scientific Notation
The number in scientific 5.67 x 10^5 -->567,000
notation are made up of 3 Exponent
parts: the coefficient, the base
Coefficient Base
and the exponent.
When the exponent is positive we move the decimal
REMEMBER: The to the right, when it is negative we move to the left.
coefficient must be So in the one above we move it to the right, while the
greater than or equal to one below we move to the left
1, but greater than 10,
The base must be 10, 9.02x10^-7 --> 0.000000902
exponent shows the
number of decimal When we do it reversed, the rules apply. When the
places that the decimal number is positive we move it to the left 10 spaces so
moved the exponent is 10.
56,760,000,000 --> 5.676x10^10
4. Scientific Figures
Digits from 1-9 are always significant. 0.007- there is
only one
If the number does have a decimal all the significant
zeros to the left will not count as a significant digit.
digits until there is a significant digit.
If the number does not have a decimal, the 5057- there are
zeros will not count as a significant digits four
significant
until there is a significant digit. digits.
Just make sure to count out the zeros correctly
and keep in mind that the zeros that are in
between the numbers are considered
significant.
5. Periodic Table
Elements are organized on the table according to 118 k
nown
their atomic number, usually found near the top ofele
ment
the square. s!
The columns of elements are called groups or
families, each horizontal row of elements is called a
period.
Elements in each family have similar by not identical
properties
The elements in a period are not alike in properties
There are three main types of elements: Non-Metals,
Metals and Metalloids
6. Calculating density
Density = mass/Volume
Density is the degree of compactness of
a substance(Usually density is expressed
in grams/milliliter)
basically you divide the mass by the
volume. D=9g/3cm^3
D= 3g/cm^3
If you have a small box, and it has a
mass of 9g and a volume of 3cm^3 find
the density.
