View
4
Download
0
Category
Preview:
Citation preview
Unit 1: Atoms, Elements, and Compounds
Grade 9 Science
Chapter 1: Atomic theory
explains the composition and
behaviour of matter.
Grade 9 Science... Unit 1
Lab Safety... A Review
Safety MUST be your top
priority.
Know them before you do the
lab and use them while doing the
lab.
Complete activity 1-1A pg. 9
Laboratory Safety
Safety Rules for the Science Lab
pages 10-11
General
Glassware
Chemicals
Hot plates and open flames
Electrical equipment
WHMIS... Page 12
W workplace
H hazardous
M materials
I information
S system
Hazard Symbols... Page 13
Dangerous
Container
Dangerous
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
of matter that
are often
observed or
measured.
Can be either
qualitative
(observed) or
quantitative
(measured).
•Color
•Malleability
•Lustre
•Conductivity
•Boilingpoint
•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, water, 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
small
Energy levels
The Atom
Recommended