Transcript Chapter 4-1 & 4-2: The Periodic Table

Chapter 4 Notes:
The Periodic Table
How would you organize the
following items?
Chp 4-1
Periodic Law
 Periodic law - periodic
table is organized based
on the atomic #, chemical
& physical properties of
the elements
 Mendeleev is the creator
of the periodic table used
atomic mass
The Periodic Table
 Group
 A vertical columns
 Elements in a group share the same chemical
properties
 Period
 A horizontal rows
 Elements in the same period have the same
number of energy levels
The Periodic Table
 Elements’ chemical properties are
determined by the number of valence
electrons
 Valence electrons are electrons that are in
the outermost energy level of an atom (in the
S and P orbital)
Main Group Elements
Transition Elements
Inner Transition
Elements
Main Group
Metals Properties
Metals Properties
 Most elements are metals
 They are good conductors of electricity
 Most are ductile (can be rolled into wire)
and malleable (can be hammered or rolled
into sheets)
 Can form alloys - solid or liquid mixtures
of metals
Check-In
A = metals
B = non metals
C = metalloids
Classify the following elements:
1.Na
2.H
3.C
4.Ca
5.Si
6.W
Alkali Metals
 Group 1
 Highly reactive (easily combine with other
elements)
 React with water to make alkaline (basic)
solutions
 Will give away 1 valence electron
 Found in nature as compounds
Alkaline Earth Metals
 Group 2
 2nd most reactive group
 Found in nature in
compounds
 Give away 2 v.e.
Transition Metals
 d and f blocks
 Most lanthanides and
actinides (f-block) are
radioactive.
 Generally less reactive
than alkali and alkaline
earth metals
Halogens
 Group 17
 Gain 1 electron in reactions
 React with metals to form salts
 Halogens are non-metals
 Seven valence electrons making them
highly reactive
Noble Gases
 Group 18
 Not reactive at all
 Eight valence electrons makes them very
stable (outermost energy level is full)
 Also called inert gases because of their
low reactivity
Hydrogen
 Most common element in the universe
 Found in many organic compounds
Chp 4-3
Periodic Trends
 Atomic radius
 Ionization energy
 Electronegativity
 Electron affinity
Periodic Trends
 Atomic Radius: The estimated distance
from the nucleus to the outer most
electrons
 Increases down a group
 As electrons energy levels are added,
the nucleus becomes larger
 Decreases across a period
 # protons increases which pulled the
v.e. closer to the nucleus
Atomic Radius Trend
Radius Increases
Radius decreases
Radius decreases
Periodic Trends
 Ionization Energy - The energy required to
remove one electron from an atom or ion
 Decreases down a group
 Electrons are farther from the nucleus and
easier to remove
 Increases across a period
 Electrons are closer to the nucleus
Periodic Trends
 Electronegativity - the ability of an atom to
attract electrons to itself
 Decreases down a group
 Increases across a period
Periodic Trends
 Electron Affinity - the energy change that
occurs when an electron is added to a
neutral atom
 Decreases down a group
 Increases across a period
Example
 Consider the following elements:
Na,
Al,
P,
Cl
 Largest and smallest radius?
 Highest electronegavity?
Fill in your periodic table
 Color and label each
of these:
 Main-group metals
 Transition metals
 Lanthanides and
Actinides
 Nonmetals
 Noble Gases
 Metalloids
 Label with arrows
each of these trends:





Atomic Radius
Ionization energy
Electronegativity
Electron affinity
Reactivity (this is
different on each side
of the PT)