Download Grade 9 Science

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 rules and
procedures 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

Can
be
Characteristics
of matter that
are often
observed or
measured.
either
qualitative
(observed)
or
quantitative
(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
Core Lab Activity 1-2C pg. 20
Physical and Chemical Properties
Theory vs. Law
 A law is better supported
than a theory.
 Most laws are supported by
different and robust
experimental evidence.
 Theories can change or be
modified
 Laws rarely change
Atomic Theory
Atomic Theory
The descriptions of
matter and how it
behaves.
Has undergone many
modifications as new
facts became available.
An atom
consists of a
 nucleus
(of protons
and neutrons)
 electrons in
space about
the nucleus
The Atom
Inside the Atom
Subatomic
Particle
Proton (p+)
Neutron (n)
Electron(e-)
Charge Mass Location
+
Large Nucleus
neutral Large Nucleus
-
Very Energy
small levels
Early ideas... 2000 years ago
Empedocles: matter was
composed of four
“elements”; earth, air,
wind, and fire.
 460 BC
 Democritus:
eventually a
substance will be
cut into a piece
that can no longer
be cut.
 He called this
piece atomos.
Aristotle
All matter was composed of
four elements
Earth, air, water and fire
Development of
Atomic Theory
 John Dalton - 1808
 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 -
1898
 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 -
1910
 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
• 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.
Rutherford’s Experiment
• they fired Helium nuclei at a piece of gold foil which was only
a few atoms thick.
They found that while most of
Gold foil
the helium nuclei passed
through the foil, a small number
were deflected and, to their
surprise, some helium nuclei
bounced straight back.
Helium nuclei
 Rutherford’s new evidence allowed him to propose a
more detailed model with a central nucleus.
 He suggested that the positive charge was all in a
central nucleus. With this holding the electrons in
place by electrical attraction
 However, this was not the end of the story.
Niels Bohr - 1913
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
Summary...