Download Atoms and the Periodic Table

• All matter is made of one or more
elements.
• The atom is the smallest particle of an
element.
• Central nucleus surrounded by one or
more electrons.
• The three subatomic particles are called
protons, electrons, and neutrons.
• Different atoms have different #s of
subatomic part.
Proton p+
• Protons have a + electric charge.
• p+ have a mass of 1 atomic mass unit
(amu).
• p+ are found in the center core of the
atom called the nucleus.
Neutron n0
• Neutrons are electrically neutral. No
charge.
• n0 have a mass of 1 amu.
• n0 are also located in the nucleus.
Electron e• The electron has a - electric charge.
• The e- has a mass of 0.0005 amu.
(The mass of the e- is so small
compared to the p+ and n0 that it is
ignored.)
• The e- is found moving around the
outside of the nucleus. (e- cloud)
Structure / Parts of
the Helium Atom
Electron
Neutron
Proton
Electron Placement
• e- are placed in shells (energy levels,
orbitals) which are located at different
distributions from the nucleus
• The shell closest to the nuclei is the 1st
shell and can hold a max of 2 e-.
• Shell no. 2 can hold a max of 8 e-.
• Valance shells (outermost) can hold a max
of 8 e-.
The periodic table gives the following
information about each element and it’s
atoms.
• Atomic Number
• Mass Number
(Atomic Mass)
• Element (Chemical)
Symbol
• Chemical symbol - an abbreviation for
each element. It’s either 1 or 2 letters
w/ the 1st letter being capital
• atomic # - the smaller of the 2 #s.
This one # reveals 2 pieces of info. It
tells the # of p+ and e-.
• The atomic mass # (or mass #) tells
the sum of the # of p+ and n0.
• This # is used to find the # of n0
• # of n0 = mass # (rounded) – atomic #
Element
Carbon
Oxygen
Protons
and
Electrons
Neutron
Protons
Neutrons
Carbon 12
6
6
Carbon 14
6
8
Atom
Name
• ___________ called groups or families.
• Elements in each group, have _____
properties and characteristics.
• Elements in horizontal rows called _____.
Sample Periodic Table
• The periodic table is
divided into three
different regions. The
three regions are the
metals, metalloids,
and the non – metals
which include the
noble gases.
• Physical properties: hardness, shininess,
malleability, and ductility.
• Malleable material can be pounded into
shapes.
• Ductile material can be pulled out or drawn
into a long wire.
• Metals are good conductors of heat and
electricity. Most are also magnetic as well.
• Noble gases (inert gases) located in family
18. They are stable and are not reactive
with other elements. Other elements want
to be like them and have their outer shell
full.
• Elements that form the zigzag line in the
periodic table.
• The metalloids have some properties of a
metal and some properties of a nonmetal.
• For example, these elements have varying
abilities to conduct electricity.
Alkali Metals
Alkaline Earth Metals
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