Download Groups

The Periodic Law
Dmitri Mendeleev (1860) When the elements are
placed in order by increasing atomic mass,
their properties repeat in a periodic way.
Moseley (~1910)
Changed the elements’ order
from atomic mass to
atomic number.
An atom’s chemical properties are
determined by its valence (outside
energy level) electrons. The identity of the
element (what element an atom is) is
determined by the number of
protons it has.
Protons
Atoms tend to lose, gain or share electrons
in order to get an electron configuration
like a noble gas.
Elements are arranged:
Vertically into Groups
Horizontally Into Periods
Arrangement of Table
Metals
Metalloids
Nonmetals
Metals
• Over 75% of the elements are classified as
metals.
• They are located to the left and lower parts of
the periodic table.
Properties of Metals
a. Malleable
a. Capable of being shaped or formed by being
hammered
b.
c.
d.
e.
Usually shiny, gray colored
Conduct electricity
Conduct heat
Ductile
a. Capable of being drawn out into a wire
f. Usually solids at room temperature
Metals Form Cations & Alloys
A CATION forms
when an atom
loses one or more
electrons.
Mg --> Mg2+ + 2 e-
Metals are mixed
with other metals
to form alloys.
Stainless Steel Refrigerator
Nonmetals
• They are found in the upper right part of
the table.
Metals
Metalloids
Nonmetals
Nonmetal properties are more
diverse than the metals.
• solid, liquid, or gas at room temp
•usually poor heat conductors
•usually poor electrical conductors
•solids are brittle
Nonmetals Form Anions
An ANION forms
when an atom
gains one or more
electrons
Metalloids (also called semimetals)
Metals
Metalloids
Nonmetals
• They are found on
the table between
the metals and the
nonmetals.
•They have
properties of both
metals and
nonmetals.
Examples are silicon, arsenic, and germanium
Periods (Energy Levels)
Horizontally Rows
• There are 7 periods in the periodic table.
• The inner transition metals are actually
“inside” periods 6 and 7.
Periodic Trends
• Across a period, atomic radius tends to
decrease .
• Across a period, ionization energy tends to
increase .
Elements are arranged:
Vertically into
Groups (also called
chemical families)
Groups
• Eight tall groups of main group
(representative) elements, numbers
ending in A, or #1-2 & 13-18.
• Ten shorter groups of transition metals,
numbers ending in B or #3-12.
• Elements in the same group have the
same valence electron configuration, and
therefore have similar chemical and
physical properties.
Down a group, atomic
radius increases and
ionization energy
decreases.
Increasing
Increasing
Group 1A: Alkali Metals
Properties
Group or Family Members
Alkali
Metals
reacting
with water:
•
•
•
•
•
Li (Lithium) – least reactive
Na (Sodium)
K (Potassium)
Rb (Rubidium)
Cs (Cesium) – more reactive
What would you expect
from Francium?!?!
Group 1A: Alkali Metals
Properties
Valence electron
configuration (period)s1
1) Soft,
silvercolored
metals
2) Highly reactive
with H2O to form
alkaline solution.
Group 1A: Alkali Metals
Properties cont.
3) They tend to form +1 ions
Li --> Li1+ + 1 e-
4) Low density (some
float in water
They are part of the s block.
Now get one color and outline the Alkali
Metal Family.
Group 2A: Alkaline Earth Metals
Silvery-White Metals
Many are found in
rocks in the earth’s
crust
Group 2A: Alkaline Earth Metals
cont.
Valence electron
configuration (period) s2
Group 2A: Alkaline Earth Metals
Properties
1)react w/water to form alkaline solution
2)not as reactive as Group 1
3)not as soft as Group 1
4)tend to form +2 ions
Mg --> Mg2+ + 2 e-
Part of the s-block
Now get one color and outline the Alkaline Earth
Metal Family.
Groups 3B through 2B or 3 through
12 Transition Metals
Groups 3B through 2B or 3 through
12 Transition Metals Properties
1) often form
colored compounds
2) harder than Groups 1 and 2
Groups 3B through 2B or 3 through
12 Transition Metals
Many of these elements can form ions with
varying charges, such as Fe+3/Fe+2, Cu+2/Cu+1
Part of the d-block
Now get one color and outline the Transition
Metals
Groups 3A or 13: Boron Family
(sometimes known as Aluminum Family)
Valence electron
configuration
(period) s2 p1
Properties become
more metallic down
the group.
Part of the p -block
Now get one color and outline the Boron Family
(sometimes known as Aluminum Family)
Groups 4A or 14: Carbon Family
nonmetals C
metalloids Si, Ge
metals Sn, Pb
Groups 4A or 14: Carbon Family cont.
Valence electron
configuration (period) s2 p2
Properties become more
metallic down the group.
Part of the p -block
Groups 4A or 14: Carbon Family cont.
Elements that exist in more than one form are
called allotropes.
An example is carbon in forms of
Graphite
Diamonds
Buckyballs
Amorphic
Now get one color and outline the Carbon
Family
Group 5A or 15: Nitrogen Family
nonmetals N, P
metalloids As, Sb
metals Bi
Group 5A or 15: Nitrogen Family
Valence electron configuration (period) s2 p3
Properties become more
metallic down the group.
Nonmetals tend to form ions with
- 3 charge. N --> N3- + 3 ePart of the p -block
Now get one color and outline the Nitrogen
Family
Group 6A or 16: Oxygen Family
nonmetals O, S, Se
metalloid Te
metals Po
Valence electron configuration (period) s2 p4
Group 6A or 16: Oxygen Family
Properties become more
metallic down the group.
Nonmetals tend to form ions with - 2
charge. O --> O2- + 2 ePart of the p -block
Important allotropes from this group are oxygen
in forms O2, oxygen gas and O3, ozone
Now get one color and outline the Oxygen
Family
Group 7A or 17: Halogen Family
(“saltmakers”)
Members – all nonmetals
F, Cl, Br, I, At
Valence electron configuration (period) s2 p5
Part of the p -block
Group 7A or 17: Halogen Family
(“saltmakers”) cont.
Very reactive, electronegative
(measurement of the attraction for
electrons) because these atoms need
only one electron to have the same
electron configuration as a noble gas.
Tend to form ions with - 1 charge.
F --> F1- + 1 e-
Now get one color and outline the Halogen
Family
Group 8A or 18: Noble Gases
Sometimes called “inert gases,”
though most can be made to react.
Valence electron configuration for He 1s2, all
others (period) s2 p6
Group 8A or 18: Noble Gases cont.
Properties
1. all are gases at room temp
2. relatively unreactive
Part of the p -block
They have no common ionic charge because
they don’t form ions, have stable electron
configurations
Now get one color and outline the Noble
Gases
Compiled by Diddy Pedraza