The periodic table arranges elements by atomic number and recurring properties. It contains 18 groups and 7 periods. Groups 1-2 and 13-18 are representative elements including alkali metals, alkaline earth metals, and noble gases. Groups 3-12 are transition metals. The document discusses common properties of several groups including alkali metals, alkaline earth metals, transition metals, and halogens. It also covers valence electrons, atomic radius, ionization energy, electron affinity, and electronegativity trends in the periodic table.

1. The Periodic Table

2. The Periodic Table
• The periodic table is a tabular arrangement of the chemical elements,
ordered by their atomic number, and recurring chemical properties.
• A group or family is a column of elements in the periodic table. There
are a total of 18 numbered groups in the periodic table
• A period or series is a row of elements in the periodic table. In the
periodic table, there are a total of seven rows.

4. The Periodic Table has 18 groups. Groups 1 – 2 (Group 1 A and 2 A) and 13 –
18 (Group 3A to 8A) are known as the Representative elements.
• Group 1A is known as the Alkali Metals
• Group 2A is known as the Alkaline Earth Metals
• Group 3A is known as the Boron Group
• Group 4A is known as the Carbon Group
• Group 5A is known as the Nitrogen Group
• Group 6A is known as the Chalcogens Group or Oxygen Group
• Group 7A is known as the Halogens
• Group 8A is known as the Noble Gases (all groups except the Noble gases
interact with other elements to be stable. Noble Gases have 8 complete
electrons, they are already stable, they don’t need to interact with other
elements).
• Groups 3 to 12 (Groups 1B to 8B) are known as the transition metals

5. Properties of Alkali Metals
The Alkali Metals have the following properties in common:
• They have low melting and boiling points compared to most other
metals
• They are very soft and can be cut easily with a knife They have low
densities.
• Lithium, sodium and potassium will float in water
• They react quickly with water, producing hydroxides and hydrogen gas

6. Properties of Alkali Earth Metals
The Alkaline Earth Metals have the following properties in common:
• They are shiny
• They are silvery - white
• They are somewhat reactive at standard temperature and pressure
• They have low densities
• They have low melting points
• They have low boiling points

7. Properties of Transition Metals
The Transition Metals have the following properties in common:
• They are very hard, usually shiny, ductile and malleable
• They have high melting points
• The have high boiling points
• They have high thermal conductivity
• They have high electrical conductivity
• They have high densities

8. Properties of Halogens
The halogens have the following properties in common:
• They are poor electrical conductors
• They are poor thermal conductors
• They form brittle solids
• They have low melting points
• The have low boiling points

9. • Valence electrons are electrons found on the outermost energy level.
The outermost energy level or shell is known as the valence shell.
For Representative elements (Groups 1A to 8A):
the number of valence electrons is equal to its group number.
For example:
Oxygen is found on Group 6A. Therefore, oxygen has six valence
electrons.
Neon is found on Group 8A, a noble gas. Therefore, neon has
eight valence electrons.

10. For Transition Metals:
Group 1B – 1 or 2 valence electrons
Group 2B – 2 valence electrons
Group 3B – 3 valence electrons
Group 4B – 2 to 4 valence electrons
Group 5B – 2 to 5 valence electrons
Group 6B – 2 to 6 valence electrons
Group 7B – 2 to 7 valence electrons
Group 8B – 2 or 3 valence electrons

11. TRENDS IN ATOMIC PROPERTIES IN THE
PERIODIC TABLE
Atomic Radius
Ionization Energy
Electron Affinity
Electronegativity

12. Atomic Radius
– size of the atom
In the Periodic Table of Elements as you move:
Downward – atomic radius increases
Right – atomic radius decreases

14. Ionization Energy
– is the amount of energy needed to remove an
electron from an atom
- lowest on Francium, because its valence electron is
farthest from all of the nucleus
- highest on Helium
In the Periodic Table of Elements as you move:
Left to Right – ionization energy increases

15. Electron Affinity
– is the amount of energy needed to gain electron from
an atom
- Flourine has the highest Electron Afinity
- Noble gases is not affected
In the Periodic Table of Elements as you move:
Left to Right – electron afinity increases

16. Electronegativity
– is the ability of an atom to hold electrons tightly
- Flourine is the highest effective nuclear charge
- Noble gases is not affected
In the Periodic Table of Elements as you move:
Left to Right – electronegativity increases