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Grade 9 Science
Unit 1: Atoms, Elements,
and Compounds
Grade 9 Science... Unit 1
Chapter 1: Atomic theory
explains the composition and
behaviour of matter.
Lab Safety... A Review
Safety MUST be your top
priority.
Know them before you do the
lab and use them while doing the
lab.
Laboratory Safety
Complete activity 1-1A pg. 9
Safety Rules for the Science Lab
pages 10-11
General
Glassware
Chemicals
Hot plates and open flames
Electrical equipment
WHMIS... Page 12
W
H
M
I
S
workplace
hazardous
materials
information
system
Hazard Symbols... Page 13
Dangerous
Dangerous
Container
Contents
Properties of Matter
Matter is anything that has mass
and volume.
Mass is the amount of matter in a
substance or object.
Volume is the amount of space a
substance or object occupies.
Matter is made up of elements.
Elements are substances that
contain one type of matter and
cannot be broken down or
separated into simpler
substances.
Describing Matter
1. Physical Properties pg. 18
Characteristics Can be either
of matter that
qualitative
are often
(observed) or
observed or
quantitative
measured.
(measured).
•Color
•Malleability
•Lustre
•Conductivity
•Boiling point
•Melting point
•Texture
•Magnetism
•Density
2. Chemical Properties pg. 19
Observed
when
substances
react with
each other.
Determines a
substances
usefulness.
•Reactivity
•Combustibility
•Toxicity
Core Lab Activity 1-2C pg. 20
Physical and Chemical Properties
Theory vs. Law
A theory is less well supported
than a law.
Most laws are supported by
different and robust
experimental evidence.
Atomic Theory
The descriptions of matter and
how it behaves.
Has undergone many
modifications as new facts
became available.
Early ideas... 2000 years ago
Empedocles: matter was
composed of four “elements”;
earth, air, wind, and fire.
Democritus: eventually a
substance will be cut into a piece
that can no longer be cut. He
called this piece atomos.
Development of Atomic Theory
John Dalton (1766-1844)
He suggested that the particles that
make up matter are like small, hard
spheres that are different for
different elements.
He defined an atom as the smallest
particle of an element.
Dalton’s Model... Billiard Ball
Model
J.J. Thomson (1856-1940)
He suggested that all atoms must
contain electrons (negative
charge).
His model pictured a positively
charged ball with the negatively
charged electrons embedded in
it.
Thomson’s Model... Raisin Bun
Model
Ernst Rutherford (1871-1937)
He discovered that atoms have a
nucleus.
There are two kinds of particles in
the nucleus; protons (positive
charge) and neutrons (neutral).
Rutherford’s Model... Planetary
Model
Niels Bohr (1885-1962)
He proposed that electrons
surround the nucleus in specific
energy levels or shells.
Each electron has a particular
amount of energy.
Bohr’s Model... Orbital Model
• Rutherford was able to develop
Thomson’s model due to the
development of new
technologies. (gold foil experiment)
• The development of cyclotrons
and proton accelerators have
further developed the model
accepted today.
Summary...
Inside the Atom
Subatomic
Particle
Charge Mass Location
Proton (p+)
+
Large Nucleus
Neutron (n)
0
Large Nucleus
Electron (e-)
-
very Energy levels
small
The Atom