Periodic Table of Elements
Standards 7.a.c.
Topic 1: Elements and Their Properties
Standards 7.c.
Elements
An element is a pure substance of one type of atom
with a specific atomic number.
  Elements are represented by symbols with atomic
numbers and atomic masses.
  The atomic number tells the number of protons.

Element Properties


Not only do elements differ based on their atomic number,
but they also differ based on their properties.
Every element has a different melting temperature, boiling
point, density, hardness, electrical conductivity, and thermal
conductivity.
Element Properties
No two elements will have
the same properties.
  For example, Calcium has
a density of 1.54g/mL
with no other element
having this same density.

Think-Check

A.
B.
C.
What makes an oxygen
element different from
calcium element?
The atomic number which
gives the number of
neutrons.
The atomic number which
gives the number of
protons.
The atomic number which
gives the number of
electrons.

Using the data on the
table below. What can be
concluded about the two
substances?
Melting Point (°C)
A.
B.
C.
Substance A
212°C
Substance B
178°C
The substances are
different elements.
The substances are the
same element.
The substances have the
same number of protons.
Topic 2: Regions of the Periodic Table
Standard 7.a.
Periodic Table & Elements


There are over a hundred known elements in the universe.
Elements are organized onto the periodic table.
Periodic Table & Atomic Number


The elements are arranged on the periodic table according to their atomic numbers.
On the table the atomic numbers increase from right to left.
Metals, Nonmetals, and Semimetals

The periodic table of elements is organized into
metals, nonmetals, and semimetals.
Metals

Metals are located on the left.
Nonmetals and Inert Gases

Nonmetals are located on the right. With the inert
gases on the far right (group 18).
Semimetals

Semimetals are found between the metals and
nonmetals.
Think-Check
What pattern is
observed on the
periodic table?
A.  Density increases
from left to right.
B.  Reactivity increases
from left to right.
C.  The atomic number
increases from left to
right.


In what region would
metals be found?
(3)
(1)
A.
B.
C.
1
2
3
(2)
Topic 3: Categories of Elements
Standards 7.a.c.
Metals
What are metals?



Metals are shiny, and
they conduct heat and
electric current.
They also tend to be
malleable and ductile.
The most reactive of the
metals are found on the
far left of the periodic
table (groups 1 and 2).
Nonmetals
What are nonmentals?



Nonmetals are dull and
poor conductors of heat
and electric current.
The solid nonmetals tend
to be brittle and
unmalleable.
The most reactive of the
elements are found on the
far right of the periodic
table (group 17).
Nonmetals - Inert Gases


The inert gases, also
known as noble gases,
are found in group 18
and tend to be
unreactive.
In normal conditions,
they do not react with
other elements.
Semimetals
What are semimetals?


Semimetals, also known
as metalloids, have
properties of both
metals and nonmetals.
Semimetals have unique
electrical properties
(semiconductors) that
make them useful in
computer chips.
Think-Check

A.
B.
C.
What are properties of
metals, nonmetals, and
semimetals?
Metals = dull
Nonmetals = shiny
Semimetals = semiconductor
Metals = shiny
Nonmetals = dull
Semimetals = semiconductor
Metals = shiny
Nonmetals = semiconductor
Semimetals = dull

In what region would the
most reactive elements be
found?
(1)
(3)
(2)
A.
B.
C.
1
2
3