SECTION 2: METALS,
NONMETALS, AND
METALLOIDS
Chapter 19: Elements and their
Properties
LEARNING GOALS
Describe
the properties of typical
metals, nonmetals, and metalloids.
PROPERTIES OF METALS
Metals
can be found to the left of the
“staircase” on the periodic table.
 Almost all solid

Mercury (Hg) is the exception!
 Good conductors of heat and electricity
 They reflect light (shiny, luster)
PROPERTIES OF METALS
 Malleable: they can be hammered or
rolled into sheets
 Ductile: they can be drawn into wires
PROPERTIES OF METALS
The
atoms of metals generally have 13 valence electrons.
In
chemical reactions, metals tend to
give up electrons easily.
 When metals combine with nonmetals,
the atoms tend to lose electrons to the
atoms of nonmetals, forming ionic
bonds.
PROPERTIES OF METALS
Metallic
bonding: positively charged
metallic ions are surrounded by a
cloud of electrons.
 The outer-level electrons are not tightly
held to the nucleus and can move freely
among the charged ions.
PROPERTIES OF NONMETALS
Nonmetals:
elements that usually are
gases or brittle solids at room
temperature.
 The solids break easily (brittle) and are
not malleable or ductile.
 Most nonmetals do not conduct heat or
electricity well and are not shiny.
PROPERTIES OF NONMETALS
The
electrons of nonmetals are
strongly attracted to the nucleus of
the atom.
 They can form ionic bonds, in which
they gain electrons from metals.
 They can also form covalent bonds, in
which they share electrons with other
nonmetals.
PROPERTIES OF NONMETALS
About
90% of all atoms in the
universe are hydrogen atoms!
Hydrogen
is a diatomic molecule:
 Consists of two atoms of the same
element in a covalent bond.
 H2
 N2, O2, F2, Cl2, Br2, I2
PROPERTIES OF METALLOIDS
Metalloids
can form ionic and
covalent bonds with other elements
and can have both metallic and
nonmetallic properties.
Some
metalloids can conduct
electricity better than most
nonmetals, but not as well as metals.
PROPERTIES OF METALLOIDS
Metalloids
can also be called
semiconductors:
 Semiconductors: elements than
conduct an electric current under
certain conditions.