CH 316 Special Topics in Inorganic

Chemistry

Transition Elements,

Lanthanides, Actinides, Rare

Earth Elements and its

Application and Extraction

Dr Chamara Jayasundera Department of Chemistry, Faculty of Science

University of Peradeniya, Kandy, Sri Lanka

E Mail:- acaj@pdn.ac.lk

What :- Module CH 316

Title:- Chemistry of Transition Elements,

Lanthanide, Actinides, Rare Earth: Chemistry

and Extraction

When :- Friday 13.00 pm-14.00 pm

Where :- New Chemistry Lecture Theatre

Who :- Dr Chamara Jayasundera

Why :- To gain a knowledge and

understanding of Transition Elements,

Lanthanides and Actinides

Assessments:- Applications of Transition

Elements and/or Lanthanides and/or Actinides

The Transition Metals, the

Lanthanides and the Actinides

The Metals in the Middle

• Groups 3-12 are called the transition elements.

• All of them are metals.

• Across any period from Group 3 through 12, the properties of the elements change less noticeably than they do across a period of representative elements.

• Most transition elements are found combined with other elements in ores.

Properties – catalysis

• A catalyst is a substance that speeds up a

chemical reaction without being used up.

• Catalysts are hugely valuable in industry

where they can save time and energy.

• Many transition elements ( and their

compounds) are catalysts.

V

Ti

Used in plastic

manufacture

Fe

Ni

Used in oil

hydrogenation

Uses The three most commonly known transition

elements are iron or steel, copper and zinc.

iron or

steel

General

engineering

metal

copper

Electrical and

plumbing work

zinc

Galvanising steel

to protect it

20_435

0.2

Ato

mic

ra

dii

(nm

)

Atomic number

La

Hf

Ta

WRe Os

Ir Pt

Au

Zr

Y

NbMo

Tc Ru

Rh Pd

Ag

Sc

Ti

VCr

Mn Fe Co NiCu

1st series (3d)

2nd series (4d)

3rd series (5d)

0.1

0.15

Multiple Oxidation States

Metallic Behavior/Reducing Strength

• Lower oxidation state = more metallic

Color and Magnetism

• e- in partially filled d sublevel absorbs visible light

• moves to slightly higher energy d orbital

Magnetic properties due to unpaired electrons

Electronegativity increases down column

Uses of Transition Elements

• Chromium’s name comes from the Greek word for color, chrome.

• Many other transition elements combine to form substances with brilliant colors.

Chromium Chemical properties reflect oxidation state

Valence-State Electronegativity

Electronegativity, EN:

electron “pulling power”

Valence-state EN:

metal in higher oxidation state

is more positive

has stronger pull on electrons

is more electronegative

“Effective EN”