Matter

1. Discovering the
Wonders of Matter and
Atoms
Welcome to the world of matter and atoms! Let's take a fascinating
journey into the smallest constituents of everything around us.
Made by Mr.Mostafa Ebrahim

2. Structure of an Atom
The Basic Structure
Atoms are made up of a
nucleus, containing protons
and neutrons, and electrons
orbiting around the nucleus.
The Periodic Table
An organized chart of all
known elements, which is
arranged in order of
increasing atomic number and
grouped by their chemical
properties.
Electron Cloud
Electrons exist in energy
shells, or orbitals, around the
nucleus. The farther the shell
from the nucleus, the more
energy it has.

3. Protons, Neutrons, and Electrons
1 Protons
Positively charged
particles found in the
nucleus. They
determine the
element's atomic
number and therefore
the element's identity.
2 Neutrons
Neutral particles found
in the nucleus, helping
to stabilize and hold
together the nucleus.
3 Electrons
Negatively charged
particles that orbit the
nucleus in shells or
energy levels. The
number of electrons
equals the number of
protons in a neutral
atom.

4. Symbol of Elements
Elements
Substances that cannot be chemically
broken down into simpler substances by
physical or chemical means. Ex. Gold ,
which is often used in jewelry , it can be
molded, hammered , sculpted , or drawn
into wire , whatever its size or shape the
gold is still gold.
Symbol
The symbol for an element is derived
from its name, often taken from Latin or
Greek, and is a one- or two-letter
abbreviation (like Au (aurum) for gold).
And mercury ( Hg for hydrargyrum)
Molecular Formula
Molecular formulas give the kind and number of atoms of each element present in the
molecular compound. The molecular formula for water, for example, is H2O, signifying that
it is made up of two hydrogen atoms and one oxygen atom.

5. Atomic/Mass number and Isotopes
1 Atomic Number
This number equals the number of protons in an atom and defines the element.
2 Mass Number
The sum of protons and neutrons in an atom's nucleus.
3 Isotopes
Atoms of the same element with different numbers of neutrons are called isotopes.
They have the same atomic number but different mass numbers.
4 Examples
Carbon-12, carbon-13, and carbon-14 are all isotopes of the element carbon. They
have 6 protons but different numbers of neutrons in their nuclei.

7. Valence Electrons and Ions
Valence Electrons
Electrons in the outermost energy level of an
atom. They determine how an atom will bond
with other atoms to form molecules.
Ions
An ion is formed when an atom either gains or
loses an electron to achieve a full outer shell and
become more stable. Ionic bonds are formed by
the attraction between ions of opposite charges.

8. What Elements Are Most Abundant?
Most Abundant Elements in the
Universe:
Much Less Abundant Elements in
the Universe:
Hydrogen Sulfur
Helium Calcium
Oxygen Silicon
Carbon Titanium