Week 11/The Periodic Table of Elements

THE ELECTRONIC CONFIGURATION

GENERAL CHEMISTRY 1

11

The ELECTRONIC CONFIGURATION

● Write electronic configuration of atoms
● Determine the magnetic property of atom based

on its electronic configuration

● Perform exercises on writing electronic

configuration

11

GENERAL CHEMISTRY 1

https://www.youtube.com/watch?v=TjVrcw2sZLs

11

GENERAL CHEMISTRY 1

https://www.youtube.com/watch?v=fPnwBITSmgU

11

GENERAL CHEMISTRY 1

History of the Periodic Table

• 1871 – Mendeleev arranged the elements

according to: 1. Increasing atomic mass 2.
Elements w/ similar properties were put in the
same row.

• 1913 – Moseley arranged the elements

according to: 1. Increasing atomic number 2.
Elements w/ similar properties were put in the
same column.

11

GENERAL CHEMISTRY 1

Multiple Choice

Who arranged the modern Periodic Table of Elements?

• Marie Curie
• Dmitri Mendeleev
• Isaac Newton
• Albert Einstein

11

GENERAL CHEMISTRY 1

Increasing energy

1s

2s

3s

4s

5s
6s
7s

2p

3p

4p
5p
6p

3d

4d
5d

7p
6d

4f
5f

Review of Electron

Configuration

11

GENERAL CHEMISTRY 1

Periodic Table & Electron Configuration

11

GENERAL CHEMISTRY 1

Periodic Groups

• Elements in the same column have similar

chemical and physical properties.

• These similarities are observed because

elements in a column have similar e-
configurations (same amount of electrons
in outermost shell).

11

GENERAL CHEMISTRY 1

Multiple Choice

Which is TRUE about the groups in Periodic Table of Elements?

• Elements in the same group have identical symbols.

• Elements in the same group are all metals.
• Elements in the same group have similar chemical properties.
• Elements in the same group have different atomic numbers.

Know the Group Names

11

GENERAL CHEMISTRY 1

Periodic Trends

•

Trends we’ll be looking at:

1. Atomic Radius and Ionic Radius
2. Ionization Energy
3. Electronegativity
4. Reactivity
5. Metallic Character

11

GENERAL CHEMISTRY 1

Atomic Radius

• Atomic Radius –

size of an atom
(distance from
nucleus to
outermost e-).

11

GENERAL CHEMISTRY 1

Atomic Radius Trend

• Group Trend – As you go down a column, atomic

radius increases.

As you go down, e-are filled into orbitals (energy levels)

that are farther away from the nucleus (attraction not
as strong).

• Periodic Trend – As you go across a period (L to R),

atomic radius decreases.

As you go L to R, e-are put into the same energy level,

but more p+and e-total (more attraction = smaller
size).

11

GENERAL CHEMISTRY 1

Multiple Choice

Which is TRUE about the atomic radius in the Periodic Table of Elements?

• Atomic radius remains constant down a group and across a period.
• Atomic radius decreases down a group and increases across a period.
• Atomic radius is the same for all elements in the Periodic Table.
• Atomic radius increases down a group and decreases across a period.

Ionic Radius

• Ionic Radius -

size of an atom when it is an ion.

11

GENERAL CHEMISTRY 1

Ionic Radius Trend

• Metals – lose e-, which means more p+than e-

(more attraction) SO…

Ionic Radius < Neutral Atomic Radius

• Nonmetals – gain e-, which means more e-

than p+(not as much attraction) SO…

Ionic Radius > Neutral Atomic Radius

11

GENERAL CHEMISTRY 1

Ionic Radius Trend

• Group Trend – As you go down a column,

atomic radius increases.

• Periodic Trend – As you go across a period (L

to R), atomic radius decreases.

11

GENERAL CHEMISTRY 1

Multiple Choice

Which is TRUE about the ionic radius in the Periodic Table of Elements?

• Ionic radius increases down a group and decreases across a period.
• Ionic radius increases across a period and remains constant down a group.
• Ionic radius remains constant down a group and across a period.
• Ionic radius decreases down a group and increases across a period.

Ionization Energy

• Ionization Energy – energy needed to remove

outermost

11

GENERAL CHEMISTRY 1

Ionization Energy

• Group Trend – As you go down a column, ionization

energy decreases.

As you go down, atomic size is increasing (less

attraction), so easier to remove an e-.

• Periodic Trend – As you go across a period (L to R),

ionization energy increases.

As you go L to R, atomic size is decreasing (more

attraction), so more difficult to remove an e-

(also, metals want to lose e-, but nonmetals do
not).

11

GENERAL CHEMISTRY 1

How do electron configurations explain why
there is a big change in energy at the red line?

Energy to Take Off Several Electrons

11

GENERAL CHEMISTRY 1

Electronegativity

• Electronegativity- tendency of an atom to attract.

11

GENERAL CHEMISTRY 1

Electronegativity Trend (really

electron affinity)

• Group Trend – As you go down a column, electron

affinity decreases.

As you go down, atomic size is increasing, so less

attraction of electrons to the nucleus.

Periodic Trend – As you go across a period (L to R),

electron affinity increases.

As you go L to R, atomic size is decreasing, so the

electrons are more attracted to the nucleus.

11

GENERAL CHEMISTRY 1

Multiple Choice

Which is TRUE about the electronegativity in the Periodic Table of Elements?

• Electronegativity increases across a period and decreases down a group.
• Electronegativity decreases across a period and increases down a group.
• Electronegativity is constant across a period and varies randomly down a group.
• Electronegativity increases down a group and remains the same across a period.

Reactivity

• Reactivity – tendency of an atom to react.
• Metals – lose e-when they react, so metals’

reactivity is based on lowest Ionization Energy
(bottom/left corner)
– Low I.E = High Reactivity.

• Nonmetals – gain e-when they react, so

nonmetals’ reactivity is based on high
electronegativity (upper/right corner).
– High electronegativity = High reactivity

11

GENERAL CHEMISTRY 1

Metallic Character

•
Properties of a Metal –
– Easy to shape (malleable); many are ductile

(can be pulled into wires)

– Conduct electricity and heat
– Shiny

•

Group Trend – As you go down a column, metallic character increases
(because ionization energy decreases).

•

Periodic Trend – As you go across a period (L to R), metallic character
decreases (because ionization energy decreases) (L to R, you are
going from metals to nonmetals).

11

GENERAL CHEMISTRY 1

Do This…

• Based on these trends, can you describe some

properties of the following groups?

• Alkali
• Alkaline
• Halogens
• Noble Gases

– Also, be able to identify metals, transition metals

semi-metals, and non-metals and know some
properties of each.

11

GENERAL CHEMISTRY 1

https://www.youtube.com/watch?v=hePb00CqvP0

11

GENERAL CHEMISTRY 1

11

GENERAL CHEMISTRY 1