Metals and Nonmetals
Metals and Nonmetals on the Periodic Table
Properties of Metals and Nonmetals
Mixtures, elements, and compounds
● Scientists classify matter by its composition
● Ultimately, all matter can be classified as mixtures, elements, or compounds
Elements
● Elements are the simplest forms of pure substances.
● They cannot be broken down into anything else by physical or chemical processes.
● The smallest particle of an element that has the properties of that element is called
an atom. An atom is the basic building block of matter.
● There are more than one hundred known elements in the universe listed on the
periodic table of elements. These elements combine in such a way to create millions
of compounds.
● All elements are made of atoms.
● Atoms of the same elements are alike.
● Atoms of different elements are different.
Compounds
● Pure substances that are the unions of two or more elements are called compounds.
They can be broken down into simpler substances by chemical means.
● Compounds are also pure substances, however they are made from more than one
element.
● E.g. Water is a compound. Water can be broken down into simpler substances –
hydrogen and oxygen.
Mixtures
●
Mixtures are two or substances that are not chemically combined with each other and
can be separated by physical means.
● The substances in a mixture retain their individual properties.
● Solutions are a specific type of mixture where one substance dissolves in another.
● An alloy is a mixture of chemical elements of which at least one is a metal.
If a matter cannot be separated by physical means, it is a pure substance. These include
elements and compounds.
Classification of matter
Impacts of Elements
Age
Between year - year
Main element/
compound(s) used
Use
Copper age
c. 4500 BC-3500 BC Copper (element)
First use of metals
as tools and
weapons.
Bronze age
c.3200-1200 BC
Bronze
(alloy/mixture of
copper and tin)
Made tools,
weapons, and
armour stronger due
to metal casing
Iron age
c.1200 BC-100 AD
Iron (element)
Farm tools and
stronger, lighter
weapons
Polymer (plastic)
age
1907-present
Compound of
carbon, hydrogen,
oxygen, and
nitrogen
Commodity plastics
and engineering
plastics
Physical and Chemical Changes
What is a physical change?
● A physical change alters the form of a substance, but does not change it to another
substance. E.g. Making orange juice
What is a chemical change?
● When a substance undergoes a chemical change, it is changed into a different
substance with different properties. E.g. Baking a cake
Signs of a chemical change
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Colour change
Precipitation
○ Precipitation is the solid that forms from a solution during a chemical reaction.
○ It looks like a cloudy solid in an otherwise clear solution.
Gas production
Temperature change
Changes in characteristic properties
○ E.g. odour, light given off
Solutes, Solvents and Solutions
● A solid dissolved in a liquid makes a solution.
● In a solution the liquid is called the solvent, and the solid is called the solute.
● Solubility is the maximum amount of a substance that will dissolve in a given amount
of solvent at a specified temperature.
Terminology
● Solution - the mixture formed when a substance dissolves in it
● Solute - the substance that dissolves
● Solvent - the liquid in the solution
● Dissolve - mixing of a substance in a liquid
● Soluble - a substance which can dissolve (mix in a liquid)
● Insoluble - a substance which cannot dissolve (mix in a liquid)
Concentration
● The more solute dissolved in a solvent the more concentrated it is
● Concentration can be measured in how many grams of solute can be dissolved in
100 ml of water ( g/100ml)
A solution can be classified as saturated or unsaturated
● A saturated solution is saturated if it has the maximum amount of solute dissolved in
a volume at a particular temperature.
● An unsaturated solution is unsaturated if it has less than the maximum solute
dissolved in a volume at a particular temperature.
● A supersaturated solution is one that contains more solute than it would under
normal conditions-one can warm the solution to make more of the solute dissolve.
Separating Mixtures
Separation Techniques
● Magnetism - Separates magnetic material from non-magnetic materials
● Evaporation - Separates a soluble solid by boiling off the liquid
● Filtration - Separates an insoluble solid from a liquid
● Distillation - Separates liquids with different boiling points
● Chromatography - Separates liquids of different colours
Chemical Reactions
● Substances that react together are called reactants.
● The substances they produce are called products.
● Not all elements are able to react with other elements.
Physical Changes
● No new substance is produced, but some of the properties may change.
Chemical Changes
● Occur following a chemical reaction and the properties of the products do change.
How do we know a reaction has occurred?
● Production of Gas
● Production of Light or Heat
● Change of Mass
● Permanent Change in colour
● Formation of a precipitate
Reaction rate
The speed of a reaction is affected by:
● Temperature
● Concentration of reactants
● Size of particles of reactants
● Use of a catalysts
○ E.g. In chemical reactions that involve water, proton acids are used.
Chemistry in Industry
● We are surrounded by chemicals, some are naturally produced and others are
manufactured.
● Natural chemicals are produced by nature without any human intervention.
● Synthetic chemicals are made by humans using methods different from those nature
uses, and these chemical structures may or may not be found in nature.
● Many chemicals that are deemed unnatural are derived from natural products.
● Chemistry is used in industry to create products that we use every day such as
pharmaceuticals and polymers.