Transcript The Periodic Table of Elements

The Periodic Table of
Elements
What are atoms?
 Atoms are composed of protons,
electrons, and neutrons. The number
of protons in the nucleus of an atom is
equal to its atomic number.
 In the ground state, the number of
protons equals the number of electrons.
It also equals the number of neutrons.
 Protons = Neutrons = Electrons
What is the Periodic Table of
the Elements?
 Elements are substances that cannot be
broken down any further by chemical
means.
 The Periodic Table is the arrangement
of these elements by increasing atomic
number and similar properties.
Properties
 Chemical- A property used to characterize
materials in reactions that change their
identity.

Ex: electronegativity, pH, toxicity, reactivity,
flammability
 Physical- A characteristic of a substance
that can be observed without changing the
substance into something else.

Ex: length, color, shape, density, mass,
volume, solubility,
How is it specifically arranged?
 Periods (Rows)
 Groups (Columns)
 Atomic number
Periods



Row = Period
Period Number = Highest Unexcited Energy
Level
Why are there more elements in a period as you
move down the periodic table?
Groups






Column = Group
Share Number of Valence Electrons and
Common Properties
What is a valence shell? Outermost Shell
Same Valence Electrons = Similar Chemical
Properties
Roman Numerals = Valence Electrons
Fluorine (F) –
Roman Numeral VII
 7 valence electrons

Properties and Trends
 Properties in Comparison



Atom Size
Energy Required to Remove an Electron
from an Atom
Ability to Form a Chemical Bond
Organizing Elements
 Elements are sorted by common
properties.
 The major categories of elements are
the metals, nonmetals, and metalloids.
Metals
 What is a metal?
 Metals are lustrous, malleable, and are good
conductors of heat and electricity.
 This is because the electrons in the valence
shell of a metal has electrons that move
easily.
What are the types of metals?
 Alkali Metals
 Alkaline Earth Metals
 Transition Metals
Nonmetals
 Elements that do not share the
properties of metals.
 Halogens
 Noble Gases
Metalloids (Semimetals)
 Elements that share some, but not all the
properties of metals.
 Staircase
State
 The three states of matter are solid,
liquid, and gas.
 Most elements are solid at standard
temperature, but a few are gaseous and
only a couple are liquid.
 Noble gases are all gaseous at standard
temperature.
Atomic Mass
 How heavy an atom is.
 Calculated by adding up the masses of
the protons, neutrons, and electrons of
an atom.
 http://chemistry.about.com/library/blperio
dictable.htm