simple presentation

1. Md.Siam Sheikh-173-33-4290
Presentation on
chemistry-1
Prepared By
group name-rainbow
department of EEE
course instructor-Md.Nazrul Islam

2. The periodic table is a tabular arrangement of the chemical elements,
ordered by their atomic number, electron configuration, and recurring
chemical properties, whose adopted structure shows periodic trends.

3. In 18690 Russian chemist Dmitri Mendeleev Published a Periodic Table and
corresponding periodic law of 63 elements known at that time
Mendeleev’s Periodic Law states that “The Physical and Chemical Properties of
the elements are periodic functions of their atomic weights.”
Henry Moseley. ... Moseley's Law justified many concepts in chemistry by
sorting the chemical elements of the periodic table of the elements in a logical
order based on their physics. He published the first Long Form periodic table or
Modern periodic table which is used till date.
Henry Moseley

4. The atomic radius of a chemical element is a measure of the
size of its atoms, usually the mean or typical distance from
the center of the nucleus to the boundary of the surrounding
cloud of electrons.

6. The ionization energy (IE) is qualitatively defined as the
amount of energy required to remove the most loosely
bound electron, the valence electron, of an isolated gaseous
atom to form a cation.

7. Ionization potential across a group:
When moving to the right of a period, the number of electrons
increases and the strength of shielding increases. As a result, it is
easier for valence shell electrons to ionize, and thus the ionization
energy decreases down a group. This is due to electron shielding.
1) As you move down a group, first ionization energy decreases.
Electrons are further from the nucleus and thus easier to remove
the outermost one.
2) As you move across a period, first ionization
energy increases.

8. Electron affinity is the energy change when a gaseous atom gains an electron
To form a gaseous ion. Electron affinity can either be exothermic or very
Endothermic.
Example:
Cl +e =Cl-………………………∆H-348KJ/mole

9. Electronegativity
What is electronegativity?
Electronegativity is a measure of the tendency of an atom to attract a
bonding pair of electrons.