1. Chemical Elements
WORLD

2. BIG WORLD 1

3. BIG WORLD 2

4. BIG WORLD 3

5. BIG WORLD 4

6. SMALL WORLD 1

7. SMALL WORLD 2

8. SMALL WORLD 3

9. What is a Chemical Element?
Answer:
A chemical element, or an element, is a material which cannot be
broken down or changed into another substance using chemical
means. Elements may be thought of as the basic chemical building
blocks of matter. Depending on how much evidence you require to
prove a new element has been created, there are 117 or 118 known
elements.
All substances consist of matter. Matter is anything which has mass
and takes up space. Some important concepts to remember about
matter are:
• Matter is made up of one or more of over 92 naturally-occurring
elements.
• Each element is a pure substance, made up of only one type of
atom.

10. Hydrogen Atom

11. The Periodic Table
The periodic table is a chart which organizes the chemical elements.
The elements are categorized according to the following attributes:
• Atomic Number - number of protons in the nucleus
• Atomic Mass - sum of the number of protons plus neutrons in the
nucleus
• Atomic weight - total mass of protons, neutrons and electrons.
The unit of mass for atoms and their particles is the DALTON. A neutron
has a mass of 1.008 daltons; a proton 1.007 daltons; an electron
0.0005 daltons, hence practically all the mass of an atom is in the
nucleus.
Group - columns or multiple columns in the periodic table:
-elements in a group share similar chemical and physical properties.
Period - rows from left to right in the period table:
-elements in a period have the same number of energy shells.

12. The Periodic Table

13. Atom and Its Structure
• Chemistry is the study of matter and the
interactions between different types of matter
and energy. The fundamental building block of
matter is the atom. An atom consists of three
main parts: protons, neutrons, and electrons.
Protons have a positive electrical charge.
Neutrons have no electrical charge. Electrons
have a negative electrical charge. Protons and
neutrons are found together in what is called the
nucleus of the atom. Electrons circle around
nucleus.

14. Oxygen

15. Carbon (1)

16. Carbon (2)

17. Aluminium

18. Silver

19. Isotopes
The difference between one element and other is
due to the difference in the number of protons in
their atoms. However, some atoms of the same
element have different numbers of neutrons.
These different atoms are called isotopes of the
element. All isotopes have the same chemical
properties because the chemical properties of an
element are determined by their electrons and all
atoms of an element have the same number of
electrons.

20. Electrons
• Electrons posses different amounts of energy and
are located in numbered energy levels up to n =
7. Electron levels are sometimes called energy
shells and are labelled: K, L, M, N, etc. To achieve
stability, atoms either empty their outermost
energy levels or fill it up to the maximum. In so
doing they may give up, accept or share electrons
with other atoms, whichever is easiest. The
VALENCE (combining capacity) is the number of
of extra or deficient electrons in the valence
energy level.

21. BONDS
• ANIMAL BONDING
• HUMAN BONDING
• CHEMICAL BONDS

22. ANIMAL BONDING 1

23. ANIMAL BONDING 2

24. ANIMAL BONDING 3

25. ANIMAL BONDING 4

26. ANIMAL BONDING 5

27. ANIMAL BONDING 6

28. HUMAN BONDING 1

29. HUMAN BONDING 2

30. HUMAN BONDING 3

31. HUMAN BONDING 4

32. HUMAN BONDING 4

33. HUMAN BONDING 5

34. Chemical Compounds - Chemical
Bonds
A compound is a combination of two or more
chemically-bonded elements.
• IONIC BONDS
• COVALENT BONDS
• HYDROGEN BONDS

35. Ionic Bonds
In ionic bonds, electrons are actually transferred
from one atom to another. Such attoms or
aggregates of atoms are then called ions. The
atom gaining an electron or electrons becomes
negatively charged, called an anion. The atom
which loses electrons becomes positively
charged, called a cation. Since oppositely charged
partticles attract each other, oppositely charged
ions can be held together by this attraction to
form electrically neutral ionic compounds. Such
attracttions are called IONIC BONDS.

36. Covalent Bonds
In covalent bonds, atoms share electrons in their outer
energy level. If one pair of electrons are shared (e.g.
H2) a SINGLE covalent bond is formed. Two pairs
shared (e.g O2) form a DOUBLE bond. Three pairs (e.g.
N2) a TRIPLE bond. Shared electrons, attracted equally
to both atoms, as with H2, form a NON-POLAR
COVALENT BOND. However, if one atom attracts the
shared electrons more strongly than the other, the
bond is a POLAR COVALENT BOND and produces polar
molecules with positive and negative areas. Water is a
polar molecule.

37. Ionic & Covalent Bonding

38. Hydrogen Bonds
Oppositely charged regions of polar molecules
can attract one another. Such a bond between
hydrogen and e.g. Oxygen or nitrogen is called
a HYDROGEN BOND. These occur in water,
proteins and other large molecules but are
weak bonds (5% as strong as covalent bonds).
However, large molecules may contain many
H-bonds, e.g. between bases in DNA and can
thus give strength and three-dimensional
shape to, e.g proteins and nucleic acids.

39. Hydrogen Bonding

40. Basic Constituents of Protoplasm
ELEMENTS PERCENTAGE MAKE (H+O) MAKE (H+0+C) MAKE (H+O+C+N)
H - HYDROGEN 9.5% WATER CARBOHYDRATES PROTEINS
& LIPIDS
O - OXYGEN 65.0%
C - CARBON 18.5%
N - NITROGEN 3.2%

41. Mixtures
A mixture is defined as an impure substance made up of two or
more types of elements (atoms) or compounds or both
mechanically mixed in any proportion, and it can be further
subdivided into simpler substances by physical (mechanical)
means.
• The constituents of a mixture retain their original properties.
• The constituents of a homogenous mixture are uniformly
mixed thoroughout the mixture. The properties and
composition of a homogenous mixture are the same
throughout the mixture.
• The constituents of a heterogenous mixture are not
uniformly mixed thoroughout the mixture. The properties and
composition of a heterogenous mixture are not the same
throughout the mixture.

42. Mixtures
Examples of Mixtures
• Stainless steel is a mixture (alloy) of iron,
carbon, chromium, and nickel. Carbon gives
hardness to the mixture. Chromium and
nickel give a silvery look to the mixture.
• Potassium sulfide solution is a homogenous
mixture.
• A mixture of water and oil is heterogenous in
nature.

43. Compounds
A compound is defined as a pure substance made up of two
or more types of elements (atoms) chemically combined in
a fixed proportion, and it can be further subdivided into
simpler substances by chemical means only.
• A molecule is the smallest part of a compound, whose
properties are the same as those of the compound.
• A compound can be represented by using a chemical
formula.
• Examples of Compounds
• The chemical formulae H2O and FeS represent the
compounds water and Ferrous sulfide (Iron [I] sulfide)
respectively.

44. States of Matter
• There are five main states of matter. Solids,
liquids, gases, plasmas, and Bose-Einstein
condensates are all different states of matter.
Each of these states is also known as a phase.
Elements and compounds can move from one
phase to another phase when special physical
forces are present. One example of those forces
is temperature. The phase or state of matter can
change when the temperature changes.
Generally, as the temperature rises, matter
moves to a more active state.