Name: ________________________________
Date: ____________________
Science 10 – A1.3 Developing Ideas about Matter (Dead Guys NG)
Read your textbook pages 18–25 to complete the following notes guide.
○ Aboriginals used their knowledge about the nature of matter and its processes to help
them meet their basic needs
○ early in human history, people began to understand the relationship between
temperature and the states of matter — _______, ________, and _____
1. Define physical change and provide one example.
2. Define chemical change and provide one example.
Many scientists contributed evidence that led to our understanding of atoms.
Historical Models of the Atom
Model of atom
The Dalton Model
(John Dalton
1766-1844)
“billiard ball” model
Why model was
proposed
● to account for the
behaviour of
substances when
they interact with
each other
according to the
law of
conservation of
mass
Key features
● All matter is composed of
small indivisible particles,
called _______ that can be
neither created nor destroyed.
● All the atoms of an element
are ____________ in
properties such as size and
mass.
● Atoms of different elements
have different __________.
● Atoms of different elements
can combine in specific
________ ________ to form
new substances.
Why model was
rejected or modified
● contained
inaccuracies
regarding the relative
masses of several
atoms
● could not account for
the electric nature of
matter
Model of atom
Why model was
Key features
proposed
● to account for the
● An atom is a sphere of
existence of small
______________ charge in
negative charges
which _____________
(cathode ray particles)
particles were imbedded.
associated with the
● The negatively charged
atom
Why model was
rejected or modified
● could not account for
the production of highfrequency
electromagnetic
radiation
● could not explain the
existence of alpha
particles for radioactive
materials
● to account for the
● At the centre of every atom,
there is a small, positively
charged ___________.
● could not account for
● The nucleus accounts for the
majority of the mass of the
atom.
● included orbiting
electrons that should
constantly radiate
energy and therefore
collapse into the
nucleus, but the
radiation and collapse
were not observed
particles were called
___________.
● Electrons are extremely tiny
compared with the size of an
atom.
The Thomson model
(J.J. Thomson
1856-1940)
“plum pudding”
model
deflection and
reflection of alpha
particles from gold
foil
● Gold foil
The Rutherford model
(Ernest Rutherford
1871 – 1937)
“planet Saturn”
model
experiment → he
was surprised
when particles
were deflected by
the gold foil and
hypothesized that
the atom is mainly
_______ space but
each atom has a
tiny,
_____________
charged core.
● to account for the
production of
bright-line spectra
in hot gases and
absorption spectra
in cold gases
The Bohr Model
(Neils Bohr
1885 – 1962)
● ____________ are attracted
to the nucleus and orbit in a
cloud around the nucleus.
● _____________ surround
the nucleus in specific
__________ levels.
● each energy level has a fixed
maximum number of
electrons that can reside in it
● electrons can jump from one
energy level to another
the emission spectra
of elements
● could not explain the
existence of sublevels
within higher energy
levels, predicted by
the shape of the
periodic table
The Quantum Mechanical Model of the Atom
Features of a Simplified Modern Model of the Atom
○ today’s model of the atom (current)
○ based on theory called quantum mechanics
○ an electron can be thought of as a “cloud” of
____________ charge
o electrons exist in this “cloud” at certain
allowed energy levels (they occupy the volume
of empty space that accounts for most of the
volume of the atom)
○ the electron cloud surrounds a nucleus containing two
types of particles called _____________: ____________
and ___________
o protons have a ___________ electrical charge
o neutrons have ____ electrical charge
○ the nucleus accounts for most of the mass of the atom
○ a neutral atom always has equal numbers of electrons and
protons
Properties of Protons, Neutrons, and Electrons
Subatomic particle Relative
charge
proton
1+
neutron
0
electron
1–
Symbol
Mass (g)
Relative mass
Radius (in m)
p+
n0
e–
1.67  10–24
1.67  10–24
9.02  10–28
1
1
1/1850
10–15
10–15
smaller than 10–18
Modified True/ False
Indicate whether the statement is true or false. If false, change the identified word or
phrase to make the statement true.
______ 1.
The law of conservation of mass states that matter is neither created nor
destroyed in a reaction.
______ 2.
Electrons are particles that have a single positive charge, and are located
in the outer region of the atom.
______ 3.
John Dalton stated that all mater was made up of small particles called
atoms.
______ 4.
The Danish physicist Niels Bohr stated that protons could only exist at
certain energy levels
Multiple Choice
Use the following information to answer the next three questions.
Many atomic models were developed in the nineteenth and twentieth centuries. Four of these
models are given below.
A. Plum pudding: An atom is a positive sphere embedded with negative electrons.
B. Billiard ball: An atom is a solid sphere similar to a billiard ball.
C. Planet Saturn: An atom is compared with the planet Saturn, where the planet represents
the positively charged part of the atom and the rings represent the negatively charged
electrons.
D. Solar system: An atom consists of a tiny positively charged nucleus, surrounded mostly
by empty space containing negative electrons.
1. Which model was created by the English physicist J.J. Thomson?
A.
B.
C.
D.
A
B
C
D
2. Which atomic model was created by the New Zealand-born physicist Earnest
Rutherford?
A.
B.
C.
D.
A
B
C
D
3. Which atomic model was created by the English scientist John Dalton?
A.
B.
C.
D.
A
B
C
D
4. Which of the following is not an example in which chemistry played a role in the
lives of early North American Aboriginal peoples?
A. Aboriginal peoples used wild ginger to treat coughs, colds and flu
B. Aboriginal peoples used substances containing metals to make fireworks
C. Aboriginal peoples used ashes to break down the tough layer of mucous that
coated the hides of animals
D. Aboriginal peoples used a sticky resin made from pine gum and animal fat to
build waterproof canoes
Written Response
1. Identify three methods for preserving food. For each method, identify if it is a
physical process or chemical process.
2. Define metallurgy. Identify three metals that ancient peoples used and a use for each
metal.
3. Describe Aristotle’s view of matter.
4. What was alchemy? How did it both hinder and help the advancement of chemistry?
5. Define Lavoisier’s law of conservation of mass.
6. Describe how Bohr used light emitted from atoms to decide that electrons existed in
specific energy levels.