Download Physical Properties

Chapter 1 Science Study Notes
Physical Properties
-a characteristic or description of a substance that can be used to identify it.
The States of Matter
-a physical property, can be solid, liquid, or gas.
Hardness
-the physical property of a solid that is the measure of its resistance to being scratched or dented- ex
diamond is very hard , chalk is not very hard
Malleability
-the physical properties that allows the shape of a solid to be changed (gold is malleable)
Ductility
-the physical property of a solid that allows it to be pulled into wires EX tungsten .
Melting & Boiling point
-the physical property of when a substance changes state. Melting -solid-liquid-boiling – liquid –gas
Viscosity
-the physical property of a liquid that limits its ability to flow.
Density
-an amount of mass per unit of volume
Kg/m3 , g/cm3 , g/ml
D=M
V
Crystal Form
- the form of many minerals where you can see a regular pattern of blocks or other shape
Solubility
- the ability of a substance to dissolve in a solvent(water).
Chemical Properties
-the characteristic behaviour that happens when one substance interacts with another becoming
something new.
Combustibility
-the chemical property of a substance that allows it to burn when exposed to flame and oxygen.
Reaction with Acid
-a chemical property of a substance that describes its ability to react with acid.
Alloys-a metal made by combining two or more different metals or metals and non-metals.
EX
steel = iron + carbon
Gold jewelry = 14 carat = 58% gold
Bronze= copper + tin
1.7 Physical and Chemical Changes
Physical change – a change in the state or form of a substance that does not change the original
substance
Chemical change – the alteration of a substance into one or more different substances with different
properties
Five clues of a chemical change
1. a new colour appears
2. heat or light are given off
3. bubbles of gas are given off
4. a participate forms (solid from 2 liquids)
5. change is difficult to reverse
Chapter 2
Elements and Compounds
2.1 Models of Matter: The Particle Theory
Particle Theory
 All matter is made up of tiny particles
 The particles are always moving. The more energy they have the faster they move.
 The particles are attracted to each other. The forces of attraction are stronger when the particles
are closer
 All the particles of one substance are the same. Different substances are made of different
particles
Pure substance- a substance that contains only one kind of particle
Ex. aluminum foil only has aluminum particles or sugar only has sugar particles
Mixture – a substance that contains two or more different pure substances
Ex. Cookie, or Kool-aid
Solution – a mixture made up of liquids, solids, or gases where the solution looks similar to one
of the substances and the other is hidden in it
Ex Kool-aid or
Alloys- a metal made by combining 2 or more different metals
Ex
Bronze = Copper + Tin
Brass = Copper + Zinc
Steel = Chromium + Nickel + Iron
Heterogeneous mixture – a substance in which the different components are identifiable and
can be separated by physical means.
Ex cookie or pizza
Elements – a pure substance that cannot be broken down into simpler substances
Compound – a pure substance that contains two or more different elements in a fixed proportion
Ex. Water H2O – 2 Hydrogen with 1 Oxygen
Atom – a particle in an element, from Greek atomos means ‘indivisible’
Molecules – the combination of 2 or more atoms
2.3 Putting Metals to Work
metals – a solid that is usually shiny and malleable and a good conductor of electricity
heavy metals – metals that have a very high density.
2.7 Chemical Symbols and Formulas
Chemical Symbol – an abbreviation for the name of an element. It is made up of 1 or 2 letters. The
first letter is always capitalized and the second lower case
Chemical Formula – the combination of symbols that represents a particular compound
2.8 Atoms, Molecules, and the Atmosphere
Air = 78.02% nitrogen (N2)
21.01% oxygen (O2)
0.94% Argon and other gases (Ar)
0.03% Carbon Dioxide (CO2)
2.9 Building Models of Molecules
Models – a way to represent a thing or process
Bond – represents the forces that hold atoms together
Structural diagrams – a drawing to explain molecules in which atoms are represented by chemical
symbols and bonds by straight lines connecting the symbols.
2.11 Plant Nutrients and Fertilizers
Fertilizers – a chemical substance added to the soil to increase plant growth
Nutrients – a chemical compound necessary for growth
Photosynthesis – a chemical process during which plants combine carbon dioxide from air, water, and
energy from the sun to produce sugars and oxygen gas
Word equation – a concise way to indicate a chemical reaction between substances
2.12 Metal Refining and Extraction in Canada
Minerals – a naturally occurring compound, sometimes containing metal combined with oxygen,
sulfur or other elements
Ore – rock containing a valuable mineral
Metallurgy – the technology of separating metals from their ores
Chapter 3
3.2 Developing Models of Matter
450 BC – Empedocles
Theory that matter made up of 4 elements
 earth
 air
 fire
 water
400 BC – Democritus
 Thought matter was made up of tiny particles that could not be broken down further.
 Called particles atoms – Atomos in Greek for indivisible
350 BC – Aristotle
 Very influential in his time
 supported 4 element model and so
 it was the accepted model for 2000 years.
500-1600 AD
 Four-element model accepted
Alchemists - an experimenter who was a combination of a philosopher, mystic, magician, and
chemist. They attempted to make gold out of cheap metals.
 devised chemical symbols
 invented lab tools
1650 – Robert Boyle
 Redefined the word element
Element – a pure substance that cannot be chemically broken down into simpler substances.
 He believed air was a mixture not an element.
 Did not believe the 4 element model
1700s – Joseph Priestly
 Isolated oxygen but did not realize it was an element.

Antoine Lavoisier
Using Priestly’s work concluded air is made of oxygen and one or more gases. So air cannot be
an element.


Henry Cavendish
Isolated hydrogen and when burnt in Priestly’s oxygen produced water
So water could not be an element.
1808


now accepted that matter is made of elements
John Dalton
Created an atomic model to explain why elements differ from each other
Atomic Model – A theory proposed to explain why elements differ from each other and from nonelements.
Dalton’s Atomic Model - 1808
- Matter is made up of atoms, particles to small to be seen
- Each element had its own kind of atom, with its own particular mass
- Compounds are made when atoms of different elements join to make molecules
- Atoms cannot be created, destroyed or subdivided in chemical change
1800s – Micheal Faraday
 The current model did not explain the fact that some matter has a charge – static
Charges – a negative of positive quantity of electricity that builds up on an object

Faraday discovered atoms could gain electric charge
Ions – an atom that has become charged by gaining or losing one or more electrons
The model had to change
Modified Atomic Model
- Matter contains positive and negative charges
- Opposite charges attract, same charges repel
- Atoms combine to form molecules because of electrical attractions
1904 – J.J. Thompson
 Discovered the negatively charged part of atom – electron
Modified Atomic Model – Raisin Bun Model - Thompson
- Atoms contain particles called electrons
- Electrons have a small mass and a negative charge
- The rest of the atom is a positive sphere
- Electrons are embedded in the sphere, and the entire atom is neutral or uncharged
Nagaoka - Planetary Model
 His model had a positive sphere with electrons spinning around it like the rings of a
planet.
1911 – Ernest Rutherford
 Worked at McGill University in Canada
Did an experiment…
- Fired positive particles at thin gold foil
- Thought they would pass right through
- Some bounced back
- Must be a small strong positive part to atom, he called it the nucleus
Nuclear Model
- An atom has a tiny, dense, positive core called the nucleus.
- The nucleus is surrounded by mostly empty space with fast moving negative electrons
3.3 Inside the Atom
Subatomic Particles – the protons, neutrons, and electrons that make up atoms
Protons – particle with positive charge (p+)
- Found in nucleus
- Mass is 1
Electrons – particle with negative charge (e-)
- found in area around nucleus
- mass is 1/2000 of a proton - negligible
Neutrons – particle with no charge, uncharged (n)
- found in the nucleus
- mass is 1
Atomic Number – the number of protons in an atom
Mass Number – the sum of protons and neutrons in the nucleus of an atom
Standard Atomic Notation – an internationally recognized system used to identify chemical
substances.
Ex.
Standard notation is not used in the periodic table.
Ion - atom that has become charged by gaining or losing one or more electrons
3.4 Planetary Model of the Atom
Niels Bohr – Planetary Model
- Electrons move around the nucleus in nearly circular paths called orbits
- Electrons in different orbits have different amounts of energy
- The further the electron is away from the nucleus the more energy it has
- Electrons can only be in the orbits, not between, they can move from one orbit to another
- The first orbit holds 2 e-, the second holds 8 e-, and the third holds 8e- Electrons are more stable when they are closer to the nucleus, at a lower energy
Orbit or Energy level – a circular path around the nucleus associated with individual electrons
Excited state – the condition of an electron when it is energized enough to jump to a higher orbit
Ground state – the low-energy state that is the normal orbit of an electron
Bohr Diagrams – represents the electronic structure of an element, it shows electrons in orbits around
the nucleus in the center, a circle with the element’s symbol.
Bohr-Rutherford diagrams – shows the numbers and positions of all the sub atomic particles. It
shows electrons in orbits around the nucleus in the center, a circle with the number of protons and
neutrons in the element.
To draw Bohr-Rutherford Diagrams:
1. Draw the nucleus as a solid circle.
2. Put the number of protons (atomic number) in the nucleus with the number of neutrons
(atomic mass – atomic number) under it.
3. Place the number of electrons (same as protons) in orbits around the nucleus by
drawing circles around the nucleus.
Remember: 1st shell – 2 electrons
2nd shell – 8 electrons
3rd shell – 8 electrons
4th shell – 18 electrons.
When atom gain or lose electrons they do so to have a full outer orbit.
3.6 Isotopes and Radioisotopes
Isotope – any of two or more forms of an element, both have the same number of protons but have
different number of neutrons
Radioactive – the state of an unstable element in which nuclei may break apart, ejecting very high
energy particles
Radioisotopes – an atom with an unstable nucleus
Decay – splitting apart of unstable nuclei to produce radioactive particles
α particle – alpha particle – helium nuclei with 2 protons and 2 neutrons, cannot go through cardboard
β particle – beta particle – high energy electrons, can go through cardboard but not wood
γ ray – gamma ray – high energy electromagnetic radiation with no mass, can go through wood but not
concrete