Date post: | 23-Dec-2015 |
Category: |
Documents |
Upload: | lizbeth-lewis |
View: | 216 times |
Download: | 0 times |
Periodic TableBasic Structure
Rows and Columns The Periodic Table
has • 7 rows called
“Periods” – 1-7• 18 columns called
“Groups” – 1-18
Element Arrangement Elements are ordered from left to
right, top to bottom by increasing atomic number
Atomic numbers are 1-118
Common Properties Elements in each column, or group,
have common chemical properties• Example: all elements in Group 18 are
gases.• The collective name for this group of
elements is the “Nobel Gases”• Other groups have names as well
Lots of Information The Periodic Table can give us lots of
information about the atoms of each type of element
Chemical Symbol Each element (kind of atom) has a
unique chemical symbol. This is used as a short way of writing
the names of elements These symbols are also used when
writing chemical equations Each chemical symbol is made up of
1-3 letters
Examples of Chemical Symbols
Chemical Symbols Cont’d The first letter of each chemical
symbol is ALWAYS CAPITALIZED. All other letters in the symbol are
lowercase Writing chemical symbols properly is very important in chemistry.
Capitalizing the wrong letter may indicate a different element.
Examples of Improper Capitalization of Chemical Symbols
Cl = Chlorine (correct) CI = Carbon and Iodine (incorrect)
Co = Cobalt (correct) CO = Carbon Monoxide (incorrect)
Si = Silicon (correct) SI = Sulfur and Iodine (incorrect)
# Protons The difference
among all atoms is the number of protons it has
The smallest atom has 1 proton
The largest atom has 118 protons
Atomic Number This indicates the number of protons
in each atom of a particular element. This number is usually in the largest
font in each box. Notice that atomic numbers increase
as you look left to right across the Periodic Table
Examples of Atomic Numbers
Importance of Atomic Number
The identity of an atom is determined by it’s atomic number
Knowing the atomic number of an element can help you draw an electrically neutral atom for that element