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Lesson 01: Chemical Elements

01 Elements

All physical objects in the universe are composed of matter, all matter is composed of elements, and all elements are composed of atoms.

The Universe is Composed of Matter

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02 Atoms and Elements Atoms are made up of three types of particles…

electrons: negatively charged particles which orbit the nucleus

protons: positively charged particles which are located in the nucleus

neutrons: particles with no charge located in the nucleus

An Atom of the Element Carbon

The atomic number, which indicates the number of protons in the nucleus of an atom determines the species of element.

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Atoms with different atomic numbers are referred to as elements. The way in which all elements are displayed is via the periodic table of elements…

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The periodic table displays elements using symbols which usually involve the first and second letter of the element or are historical in nature The periodic table is constructed in such a way that displays numerous patterns that exist between the elements (discussed in unit 07).

03 Combinations of Atoms Atoms of a one element may combine to form molecules…

2 2 8H , N , S ...

Or, atoms of several different elements may combine to form multi-atomic molecules...

2 2 2H O, N O ...

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Of the two types of substances that arise from the combination of elements…

elements cannot be broken down into simpler substances

compounds can be broken down into simpler substances

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04 Origin of the Elements

Nucleosynthesis and the Big Bang The process of creating new elements by building up a nucleus with more protons and neutrons is called nucleosynthesis. This process only takes place under extreme conditions of pressure and temperature. The first period of nucleosynthesis occurred in the early moments of the universe following the big bang, creating…

hydrogen

helium

The Big Bang

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Nucleosynthesis and Supernovas

When the first stars formed, another type of nucleosynthesis began in the cores of stars forming…

helium from hydrogen, and

elements up to iron

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The stage at which iron is being formed usually results in core collapse, and a…

supernova Supernovas can create even heavier elements, up to…

uranium

Supernova (Crab Nebula)

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Other processes can transforming one element into another…

radioactive decay can break a heavy element forming lighter elements

cosmic rays can break a heavy element forming lighter elements Only tiny amounts of elements heavier than uranium, neptunium, and plutonium are known to exist in nature. All other elements have been made artificially in laboratories.

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05 Classification of the Elements Chemical elements are broadly classified as…

metals

nonmetals

metalloids

Main Classification Scheme

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When the elements are arranged in the order of their atomic numbers, elements of similar physical and chemical properties occur at specific intervals. These groups of elements with similar physical and chemical properties are called families. The main families are…

Elemental Families

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Lesson 02: Naming Inorganic Compounds

Naming Chemical Compounds

With over 10 million known chemicals, and potentially dangerous results if chemicals are combined in an incorrect manner, imagine the problem if you are in the lab and say "mix 10 grams of that stuff in with this stuff". We need to be very clear on identification of chemicals. First, two categories of chemical compounds…

Organic compounds: These contain the element carbon. Life on earth is carbon

based. Organic compounds were originally associated with living organisms, however, a large number of organic compounds have been synthesized which do not occur in nature so this distinction is no longer valid.

Inorganic compounds: All other compounds.

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Terminology

Ions: An ion is an atom or molecule which has lost or gained one or more

electrons, giving it a positive or negative electrical charge.

Anions: A negatively charged ion, which has more electrons in its electron

shells than it has protons in its nuclei, is known as an anion.

Cations: Conversely, a positively-charged ion, which has fewer electrons than

protons, is known as a cation.

Monatomic Ions: An ion consisting of a single atom is called a monatomic ion,

Polyatomic Ions: If an ion consists of two or more atoms, it is a polyatomic ion.

Oxyanions: Polyatomic ions containing oxygen, such as carbonate and

sulphate, are called oxyanions.

Notation: Ions are denoted in the same way as electrically neutral atoms and molecules except for the presence of a superscript indicating the sign of the net electric charge and the number of electrons lost or gained, if more than one.

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Common Monatomic and Polyatomic Ion Charges

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Naming Inorganic Ionic Compounds

Compound Rules

Metal Non Metal

Binary Compound

The cation is always named first and the anion second.

A cation takes its name from the name of the element.

IF the cation can assume more than one charge, the charge is specified using Roman numerals in parentheses.

An anion is named by taking the first part of the element name and adding the suffix “ide”.

Non Metal Non Metal

Binary Compound

The first element in the formula is named first and the full element name is used.

The second element is named as though it were an anion.

Prefixes are used to denote the number of atoms present.

The prefix “mono” is never used for the first element.

Polyatomic Compound

The cation is always named first.

The polyatomic ion is named second

Acids

If the anion does not contain oxygen, the acid is named with the prefix “hydro” and the suffix “ic” attached to the root name for the element.

When the anion contains oxygen, the acid name is formed from the root name of the central element of the anion or the anion name, with the suffix “ic” or “ous”. When the anion name ends in “ate”, the suffix “ic” is used. When the anion name ends in “ite” the suffix “ous” is used.

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Metal Non Metal Binary Compounds

Formula Possible Charges Charge on Metal Name

CsF 1

1x

01-x

0FCs 1x

cesium fluoride

3AlCl 1

3x

03-x

03ClAl 1x

aluminum chloride

CuCl 2

1x

01-x

0CICu 1x

copper (I) chloride

32OFe 2

3x

06-2x

03O2Fe 2x

iron (III) oxide

4PbCl 2

4x

04x

04ClPb 1x

lead (IV) chloride

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Non Metal Non Metal Binary Compounds

Important Prefixes

Subscript Prefix Subscript Prefix

1 mono 6 hexa

2 di 7 hepta

3 tri 8 ocata

4 tetra 9 nona

5 penta 10 deca

Formula Name

3BF boron trifluoride

NO nitrogen monoxide

2NO nitrogen dioxide

32ON dinitrogen trioxide

52ON dinitrogen pentaoxide

4CCl carbon tetrachloride

5IF iodine pentafluoride

64OP tetraphosphorous hexaoxide

6XeF xenon hexafluoride

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Flow Chart for Naming Binary Compounds

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Polyatomic Compounds

Formula Charge on Metal Name

42SONa sodium sulphate

42POKH potassium dihydrogen

phosphate

33NOFe +3 iron (III) nitrate

2OHMn +2 manganese (II) hydroxide

32SONa sodium sulphite

34ClONH ammonium chlorate

7224 OCrNH ammonium dichromate

24ClOCo +2 cobalt (II) perchlorate

3KClO potassium chlorate

22NOCu +2 copper (II) nitrite

4CuSO +2 copper (II) sulphate

4KMnO potassium permanganate

3722 OCrCr +3 chromium (III) dichromate

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Acids

Formula Name

HF hydrofluoric acid

HCl hydrochloric acid

HBr hydrobromic acid

HI hydroiodic acid

HCN hydrocyanic acid

SH2 hydrosulphuric acid

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Oxygen Containing Acids

Formula Name

3HNO nitrate nitric acid

2HNO nitrite nitrous acid

42SOH sulphate sulphuric acid

32SOH sulphite sulphurous acid

4HClO perchlorate perchloric acid

3HClO chlorate chloric acid

2HClO chlorite chlorous acid

HClO hypochlorite hypochlorous acid

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Flow Chart for Naming Acids

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Writing Formulas from Names

Rules for Writing Formulas

If the first ion in the compound has only one possible charge…

Simply write the names of the cation first and the anion second.

If the first ion in the compound has two or more possible charges…

Make sure you choose an appropriate number of cations and anions such that the addition of their charges adds up to zero. You must end up with a compound that has a zero charge (neutral).

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Name Formula

Iron (III) oxalate

3 22 4

3 22 4

2 2 4 3

Fe C O

2Fe 3C O

Fe C O

Lead (II) acetate decahydrate

23 2

23 2

3 22

Pb CH COO 10H O

Pb 2CH COO 10H O

Pb CH COO 10H O

Mercury (I) acetate

22 3

22 3

2 3 2

Hg CH COO

Hg 2CH COO

Hg CH COO

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Name Formula

Gold (III) sulphide

3 2

3 2

2 3

Au S

2Au 3S

Au S

Chromium (III) oxalate

3 22 4

3 22 4

2 2 4 3

Cr C O

2Cr 3C O

Cr C O

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Lesson 03: Colours of Common Aqueous Ions

A useful skill to have in chemistry is the ability to determine the…

particular species of ions present based on colour

concentration of particular species of ions based on the strength of colour

Colours of Common Ions

Ion Colour 2Fe pale green

3Fe dull yellow

2Co pink - red

4MnO purple

2Ni bright green 2

4CrO bright yellow 2

72OCr bright orange

2Cu blue

2Mn very pale pink