CH. 4: I

NTRODUCTI

ON TO

ATOMS

SE

CT

I ON

4- 5

: T

HE

PE

RI O

DI C

TA

BL E

EQ: Other than

metals, what are the other regions of

the Periodic Table?

NON-METALS

KEY: Most non-metals are poor conductors of electric current and

heat. Solid non-metals are dull and brittle.

PHYSICAL AND CHEMICAL PROPERTIES

P H Y S I C A L P R O P E R T I E S

Opposite properties of

metals Poor conductors

Dull Brittle

Not malleable or ductile

C H E M I C A L P R O P E R T I E S

Atoms of non-metals usually gain or share

electrons When metals and

non-metals react, electrons move from

metals to non-metals.

Atoms share electrons and create

MOLECULES.

NITROGEN FAMILY

Group 15 Nitrogen is 80% of Earth’s atmosphere Nitrogen occurs in nature as N2. This is a

diatomic molecule.

OXYGEN FAMILY

Group 16 Contains 3 non-metals Examples are oxygen and sulfur. Oxygen also forms a diatomic molecule.

HALOGENS

Group 17 Very reactive; all but astatine are non-metals Gains or shares one electron Examples are Chlorine and Fluorine.

INERT GAS

Group 18 These tend to be UNreactive Do not ordinarily gain, lose or share

electrons. All inert gases exist in Earth’s atmosphere.

HYDROGEN

Alone in the upper left corner of the Periodic Table

The simplest of elements Have 1 proton and 1 electron. Isotopes will

have neutrons. Most Hydrogen is combined with Oxygen to

produce water. Not classified in a family!!

SEMIMETALS

Properties of both metals and non-metals. Most common elements: Silicon and Boron. They are useful since some are

semiconductors: elements that conduct electricity under certain conditions.

SECTION 5: RADIOACTIVE ELEMENTS

Some isotopes are unstable; their nuclei do not hold together well.

An example is Uranium. See page 160 for Radioactive Decay Radioactive isotopes are used in science and

industry. They are also used in medicine.