This document provides an introduction to basic chemistry concepts including matter, elements, atoms, and the structure of the atom. It defines matter as anything that has mass and takes up space. Elements are made of only one type of atom and can be found on the periodic table, which arranges elements by their atomic number and properties. Atoms are the building blocks of matter and are made up of protons, neutrons, and electrons. The nucleus of an atom, containing protons and neutrons, is at the center and electrons orbit around it. The document also distinguishes between pure substances like elements and compounds, and mixtures which can be separated physically.

1. TERM 1 GRADE 8

2. LETS START FROM THE BEGINNING…….
WHAT IS MATTER?
MATTER IS EVERYTHING THAT HAS
A MASS AND OCCUPIES SPACE
MATTER ELEMENTS
ATOMS

3. WHAT ARE ELEMENTS?
AN ELEMENT IS A SUBSTANCE
THAT HAS ONLY ONE TYPE OF
ATOM
>> CANNOT BE BROKEN DOWN CHEMICALLY
INTO A SIMPLER FORM
>> ARE MADE UP OF ATOMS
>> FOUND ON THE PERIODIC TABLE THE PERIODIC TABLE OF
ELEMENTS
>> ELEMENTS ARE ARRANGED ACCORDING TO THEIR
ATOMIC NUMBER
>> THERE ARE 118 ELEMENTS
>> THE VERTICAL COLUMNS ARE KNOWN AS GROUPS
>> THE HORIZONTAL ROWS ARE KNOWN AS PERIODS

4. WHAT ARE ATOMS?
ATOMS ARE THE BUILDING BLOCKS OF
MATTER
>> THE ATOMS OF EACH
ELEMENT ARE DIFFERENT IN SIZE
AND MASS
>> THESE ATOMS ARE THEN
MADE UP OF SUBATOMIC
PARTICLES
>> SUBATOMIC PARTICLES ARE
SMALLER THAN AN ATOM
THERE ARE 3 SUBATOMIC PARTICLES IN
AN ATOM, NAMELY:
o PROTON – POSTIVE CHARGE (+)
o NEUTRON – NEUTRAL CHARGE
o ELECTRON – NEGATIVELY CHARGED (-)
Important
The number of:
 Electrons = atomic number
 Protons = atomic number
 Neutrons = mass number – atomic
number

5. STRUCTURE OF THE ATOM
>> THE CENTRE OF THE ATOM IS KNOWN AS THE NUCLEUS
>> PROTONS AND NEUTRONS LOCATED IN THE NUCLEUS AND TOGETHER KNOWN AS
NUCLEONS
>> ELECTRONS LOCATED ON THE RINGS OF AN ATOM
>> THE NUCLEUS OF ATOM IS POSITIVELY CHARGED AND RESPONSIBLE FOR THE ATOMS
MASS
FOR EXAMPLE: OXYGEN
PROTONS = 8
ELECTRONS = 8
NEUTRONS = 16 – 8 = 8

6. PRACTICE
DRAW AN ATOM FOR THE FOLLOWING ELEMENTS :
1. CARBON
2. NITROGEN
3. FLUORINE
4. LITHIUM

7. CLASSIFYING MATTER
MATTE
R
PURE
SUBSTANCE
MIXTURE
ELEMENT COMPOUN
D

8. WHAT IS A PURE SUBSTANCE?
A SINGLE SUBSTANCE MADE UP OF
ONLY ONE TYPE OF PARTICLE
>> PURE SUBSTANCES HAVE A
SPECIFIC PHYSICAL AND CHEMICAL
PROPERTY
>> INCLUDES ELEMENTS AND
COMPOUNDS
WHAT IS A MIXTURE?
AN IMPURE SUBSTANCE THAT
HAS 2 OR MORE TYPES OF
PARTICLES
>> CAN ONLY BE SEPERATED
PHYSICALLY
>> for example sifting, hand
sorting and filtration

9. WHAT ARE COMPOUNDS?
ARE SUBSTANCES MADE UP OF 2
OR MORE ELEMENTS
>> COMPOUNDS ARE CHEMICALLY BONDED
>> CANNOT BE SEPERATED PHYSICALLY