9-12.P.1.1. – STUDENTS ARE ABLE TO USE THE PERIODIC TABLE TO DETERMINE
THE ATOMIC STRUCTURE OF ELEMENTS, VALENCE NUMBER, FAMILY
RELATIONSHIPS, AND REGIONS (METALS, NONMETALS, AND METALLOIDS).

Protons, neutrons, electrons, mass number, and atomic
number

Number of valence electrons for elements in the main
blocks of the Periodic Table

Metallic character of a specific element based on its
location on the Periodic Table.

http://www.youtube.com/watch?v=0RRVV4Diomg
Protons
Neutrons
Electrons
The number of protons in an
atom is the same as the atomic
number. The atomic number is
listed above the element
abbreviation Silicon has 14
protons.
To determine the number of
neutrons in an atom one must
subtract the protons from the
atomic mass.
Magnesium:
The number of electrons equal
the number of protons! Atoms
have no overall electrical
charge so there must be a
balance between the positively
charged protons and the
negatively charged electrons.
Silicon also has 14 electrons
24(mass)-12(protons)=12
neutrons

The mass number, also called the atomic mass number is the total
number of protons and neutrons in an atomic nucleus.

The number of protons in the nucleus of an atom determines an
element’s atomic number. Each element has a unique number that
identifies how many protons are in one atom of that element.

Using the Periodic Table on the next slide, find the mass
number and atomic number of hydrogen, phosphorus,
and iron.

Using the periodic table, one can classify elements in many ways.
One useful way is by metals, nonmetals, and metalloids.

Most of the elements on the periodic table are classified as metals.

In the periodic table there is a stair-stepped line starting at Boron (B)
and going all the way down to Polonium (Po). All of the elements to
the left of this line except for Germanium (Ge) and Antimony (Sb)
can be classified as metals.

In this figure, everything to the left of the green elements are metals.
There are different types of metals as well: transition metals, rare
earth metals, alkali metals, alkali earth metals, and other metals.

Solid (with the exception of mercury (Hg)

Mercury can be found in thermometers

Shiny, good conductors of electricity and heat

Ductile: they can be drawn into thin wires

Malleable: they can be easily hammered into thin sheets

Metals tend to lose electrons easily

The elements to the right of the stair-stepped line are classified as
nonmetals.

Hydrogen is also classified as a nonmetal

Nonmetals have properties opposite those of metals.

Nonmetals are:

Brittle

Not malleable or ductile

Poor conductors of heat and electricity

Gain electrons in chemical reactions

Some are liquids

The elements that border the stair-stepped line are classified as
metalloids. These are also known as semimetals. They have
properties that are somewhat of a cross between metals and
nonmetals.

Metalloids tend to be economically important because of their
unique conductivity properties which make them valuable in the
semiconductor and computer chip industry. Metalloids only partially
conduct electricity.