Science: Matter And Chemical Change Pat

Front 1

The Six Changes Of State

Back 1

~ Liquid to Solid – Freezing or Solidification
~ Solid to Liquid – Melting
~ Solid to Gas – Sublimation
~ Gas to solid – Deposition
~ Liquid to Gas – Evaporation
~ Gas to Liquid – Condensation

Front 2

Two Properties of Matter

Back 2

~Physical: Describes the physical characteristics of a substance such as color, luster, density, hardness and crystal shape.
~Chemical: Describes how the substance reacts with other substances, An example would be vinegar and baking soda reacting

Front 3

Pure Substances: Elements

Back 3

A substance that cannot be broken down further
Ex) Gold

Front 4

Pure Substances: Compounds

Back 4

~A chemical combination of two or more elements in a fixed proportion
~Ex) NaCI (Sodium Chloride)
~Compounds have a very strong chemical bond. As the elements combine they lose their individual characteristics
~Compounds cannot be separated by physical means such as evaporation

Front 5

Mixtures: Mechanical Mixtures

Back 5

~You see more than one mixture
~Ex) Cookie Dough
~These are also called Heterogeneous mixtures
~These can be separated by mechanical means such as using hands or filters

Front 6

Mixtures: Solutions

Back 6

~A mixture where you cannot see the different parts
~Example: Vinegar

~These are also called homogeneous mixtures
~There is no settling in a solution
~There are no chemical bonds in solutions. When the substances join, they keep their individual characteristics.
~Solutions happen because the particles slip between each other so they are evenly distributed
~They can be separated by physical means such as boiling

Front 7

Mixtures: Suspensions

Back 7

~Suspensions are heterogeneous mixtures that look homogeneous.
~Over time, the particles settle out in a suspension.
~The particles can be separated by filters or leaving it stand over time.
~Example: Salty water

Front 8

Mixtures: Colloids

Back 8

~These are heterogeneous mixtures in which the particles don’t settle out.
~Colloid particles can often be seen in a beam of light.
~Example: Milk is a colloid

Front 9

Physical Change

Back 9

~A physical change is a change in appearance or state of a substance. Composition of the substance always stays the same.
~Example: Melting, crystallization

Front 10

Chemical Change

Back 10

~This occurs when two or more substances react and create new substances.
~Example: Vinegar and baking soda reacting

Front 11

Evidence of Chemical Change

Back 11

1. Change in color
2. Change in odour
3. Forming a solid or gas
4. Release or absorption of heat energy

Front 12

Democratis

Back 12

Greek philosopher that believed that matter could be broken down into indivisible bits called “atomos”

Front 13

Aristotle

Back 13

Another Greek philosopher that believed that everything was made of earth, air, fire and water.

Front 14

Robert Boyle

Back 14

~Experimented with gases and what happened to them under pressure
~Through experiments he became convinced that matter was made of tiny particles

Front 15

Antoine Lavoisier

Back 15

~Known as the “father of modern chemistry,” he developed a system for naming chemicals

Front 16

John Dalton

Back 16

~First person to define an element as a pure substance
~Came up with the “billiard ball” model of the atom, which was the first theory of atomic structure

Front 17

J.J Thomson

Back 17

~Discovered electrons and came up with the “raisin bun” or “plum pudding” model of the atom: This showed the atom as a positive sphere with electrons (negative charges) embedded in it

Front 18

Hantaro Nagaoka

Back 18

~Proposed the “solar system” model of the atom: This showed the atom as a positive sphere with electrons orbiting it

Front 19

Niels Bohr

Back 19

~Develops the “electron shell” model where electrons move in specific shells or orbits around the nucleus

Front 20

James Chadwick

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~Discovered the proton (positive charge) and the neutron (no charge) in the nucleus

Front 21

Electrons

Back 21

Negatively charged subatomic particles found in the cloud region of atoms

Front 22

Protons

Back 22

Positively charged subatomic particles found in the nucleus

Front 23

Neutrons

Back 23

Neutral subatomic particles found in the nucleus

Front 24

Atoms

Back 24

The basic building blocks of all matter.

Front 25

Molecules

Back 25

A group of at least two atoms held together by chemical bonds.

Front 26

Types of Elements: Metals

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~Are on the left side of the staircase…they are shiny, malleable, and ductile and conduct electricity.
~Alkali metals are the most reactive metals.

Front 27

Types of Elements: Non Metals

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~Are on the right side of the staircase…they are dull, brittle and nonconductive. They can be a solid or gas.
~Halogens (group 17) are the most reactive non-metals.

Front 28

Types of Elements: Noble Gases

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~Are in group 18 and are the most stable and un-reactive elements.

Front 29

Types of Elements: Metalloids

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~Are directly above and below the staircase…they show properties of both metals and non-metals.

Front 30

Ions

Back 30

~An ion is an atom or group of atoms that has become electrically charged
~Ionic compounds are pure substances that form as a result of the attraction of positive and negative ions

Front 31

Ionic Compounds

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~They:
 Are solids at room temperature
 Have defined crystal structure
 Conduct electricity when liquid or dissolved in water
 Have high melting points

Front 32

Molecular Compounds

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~Can be solids, liquids or gases at room temperature
~Do NOT conduct electricity when liquid or dissolved in water
~Have low melting points

Front 33

Exothermic Chemical Reaction

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~A chemical reaction that releases energy is called exothermic
~ Energy released can be heat, light, sound, and electricity
~Example: Burning wood

Front 34

Endothermic Chemical Reaction

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~A chemical reaction that absorbs or requires energy is called endothermic
~ Many require heat but could also require electricity or UV radiation
~Example: Cooking food or recharging a battery

Front 35

Reactions with Oxygens

Back 35

~Combustion
>Occurs when oxygen reacts with a substance to produce a new substance and energy
~Corrosion
>Occurs when oxygen in the atmosphere gradually reacts with a metal producing rust
~Cellular Respiration
>Occurs in only in cells and is the reaction of organic material (food) with oxygen

Front 36

The Law of the Conservation of Mass

Back 36

~States that the total mass of the reactants is equal to the total mass of the products in every chemical reaction
~When a chemical reaction takes place, matter is not created or destroyed, it is only rearranged

Front 37

Closed System

Back 37

~Is a system where matter cannot escape
~Example: a reaction in a sealed flask

Front 38

Open System

Back 38

~Is a system where matter can escape
~Example: a reaction in an open beaker

Front 39

Reaction Rate

Back 39

1. Presence of a Catalyst:
~Substances that help a reaction proceed faster without being used up themselves
~Can be found in non-living and living systems
~Example: enzymes in your body
2. Concentration of the Reactants
~A higher concentration of reactants means there are more particles around to bump into each other and react
3. Temperature of the System
~ Higher temperature speeds up the motion of the particles that makes them bump into each other and react
4. Surface area of the Reactants
~A higher surface area of the reactants means more particles are exposed and able to react with other reactant particles

Front 40

Enzyme Vs. Inorganic Catalyst

Back 40

An enzyme is an organic catalyst made of protein, and functions in living things to influence
the rate of biological reactions. An inorganic catalyst can influence the rate of a reaction in a
non-living system.

Front 41

Organizing Elements

Back 41

John Newlands recognized patterns in properties when elements were listed in order of atomic mass. He said properties of elements seemed to repeat every 8 intervals on the list

Front 42

Dimitri Mendeleev

Back 42

came up with a pattern for the elements based on their properties
~He listed the 63 known elements at the time according to their properties and left gaps for elements he was sure would be discovered in the future