SSS 1: NATURE OF MATTER

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Matter is anything that has mass and occupies space. Examples of matter include; Air, water, rocks, plants, animals, and even people. 
Matter is made up of one or more of the following: atoms, molecules, and ions. 
                STATES OF MATTER  
Matter exists in three different major states which are 
1. Solid state 
2. Liquid state  
3. Gaseous state 
           PROPERTIES OF MATTER  
The properties of matter can be grouped into two namely 
1. Physical properties 
2. Chemical properties 
       Physical properties of matter 
Physical properties are properties that are associated with physical changes. The common physical properties include 
1. Boiling point 
2. Melting point 
3. Density 
4. Hardness 
5. Malleability 
6. Crystalline form etc 
It also includes properties which may be detected by the senses e.g. Colour, odor, taste, etc.
        Chemical properties of matter 
Chemical properties are those properties that are involved when matter changes to form a new substance e.g. Rusting of iron 
                  CHANGES IN MATTER 
Changes in matter can be categorized into two namely,
1. Physical change 
2. Chemical change 
                       Physical changes 
A physical change is a change that can be easily reversed and no new substances are formed.
Examples of physical changes are 
1. Melting of solid to liquid 
2. Freezing of liquid to solid 
3. Vaporization of liquid to gas 
4. Liquefaction of gas to liquid 
5. Sublimation of solid to vapor 
6. Magnetization and demagnetization of iron rods etc.
                   Chemical changes 
A chemical change is a change that cannot be easily reversed and new substances are formed.
Examples of chemical changes are 
1. Rusting of iron 
2. Addition of water to quick lime(CaO) I.e. Slaking of lime
3. Dissolution of metals in acids
4. Dissolution of limestone in acids 
5. Fermentation of substances 
6. Burning of substances 
7. Changes in an electrochemical cell etc.

DIFFERENCES BETWEEN PHYSICAL AND CHEMICAL CHANGES 

Physical            changes

Chemical changes

1. They are easily reversible

They are not easily reversible

2. No new substances are formed

New substances are formed

3. There is no change in the mass of the substance involved

There is a change in the mass of the substance involved

4. They do not involve great heat change except latent heat

They involve a considerable amount of heat change

                           ELEMENTS 
An element is a substance that cannot be split into simpler units by an ordinary chemical process. 
Elements can be classified as 
1. Metals 
2. Metalloids (Semi-metals)
3. Non-metals 

Metals are elements that ionize by electron loss e.g. Sodium (Na), potassium (K), Magnesium (Mg), Calcium (Ca), Zinc (Zn), etc.
                 Ca → Ca2+    +   2e- 
                 Na   →  Na+  +  2e- 

Metalloids are elements that have properties that are intermediate between those of metals and non-metals e.g. Boron (B), Silicon (Si), Arsenic (As), Germanium (Ge), Antimony (Sb), etc.

Non-metals are elements that ionize by electron gain e.g. Chlorine (Cl), Oxygen (O), Fluorine (F), etc 
  Cl  + e-  → Cl 
                      COMPOUNDS 
A compound is a substance that contains two or more elements that are chemically combined. Examples of compounds are 
Water (H2O)
Sand (SiO2)
Limestone (CaCO3)
Common salt (NaCl)
Ethanol (C2H5OH)
Caustic soda (NaOH)
Washing soda (Na2CO3.H2O) etc 
                         MIXTURE 
A mixture is a substance that contains two or more constituents that can easily be separated by physical methods. Examples of mixtures are Air, Soil, Urine, Palm wine, Crude oil, Sea water, Blood, Alloy, etc

Differences between mixture and compounds 

Mixture

Compounds

1. They may be homogenous or heterogeneous

They are always homogeneous

2. Their constituents are physically bonded together

Their constituents are chemically bonded together

3. They cannot be represented by a chemical formula

They can be represented by a chemical formula

4. No new substances are formed

New substances are formed

5. Their constituents are not present in a fixed mass ratio

Their constituents are present in a fixed mass ratio

6. The properties of a mixture are the sum of those of its constituents

The properties of a compound depend on its component elements


                        IONS 
An ion can be defined as an atom or group of atoms that carries a positive or negative electric charge as a result of having lost or gained one or more electrons.
                    Types of ions 
The two types of ions are 
1. Cations 
2. Anions 
Cations are positively charged ions e.g Sodium ion (Na+), potassium ion (K+), Calcium ion (Ca2+), ammonium ion (NH4+), etc 

Anions are negatively charged ions e.g. Chloride ion (Cl−), Flouride ion  (F−), Tetraoxosulphate (VI) ion  (SO42-), Trioxocarbonate (IV) ion (CO32-), etc 
                     ASSIGNMENT 
1.   a. Explain Molecules 
b. Give five (5) examples of molecules
2. a. What is an atom?
    b. State the sub-particles of an atom 
3. Give five (5) examples of the following apart from the ones given in the note above.
a. Cations 
b. Anions

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