pumpkin fruit fly, water melon fruit fly, cucumber fruit fly
Transition Elements
1. Shri. Dr. R.G. Rathod Arts and Science college, Murtizapur
Presented by,
Dr. Gopalkrushna H. Murhekar
Shri Dr. R. G. Rathod Arts and Science, College
Murtizapur
3. ALCHEMISTS
Alchemist tried to make lead into gold.
They studies many materials and used mysterious
symbols to represent these materials.
4. TRANSITION ELEMENTS
The elements in which differentiating electron enter in (n-1)d
orbitals of (n-1)th main shell are called transition elements.
These elements are also known as bridge elements as they are
lying between s and p bolck elements in a periodic table.
Because the differenting electron in these elements enter in d
orbital so these elements are called as d-block elements.
5. Atomic Radius
The distance from centre of nucleus to the valence
shell of electron in an atom is known as atomic
radius.
Atomic radius is measured in cm.
Atomic radii actually decrease across a row in the
periodic table. Due to an increase in the effective
nuclear charge.
Within each group (vertical column), the atomic
radius tends to increase with the atomic number
number.
8. EXPLANATION
The transition metals can form a variety of ions
by losing one or more electrons.
For the first five metals the maximum possible
oxidation state corresponds to the loss of all
the 4s and 3d electrons.
Toward the right end of the period, maximum
oxidation state are not observed, in fact 2+ ions
are the most common because the 3d orbital
become lower in energy as the nuclear charge
increases, and the electrons become
increasingly difficult to remove.
9. IONIZATION ENERGY
Ionization energy, Ei: minimum
energy required to remove an
electron from the ground state
of atom (molecule) in the gas
phase. M(g) + h M+ + e.
Increase across row
But increase smaller than for
main-group elements
Also, 3rd transition row has
higher ionization E (generally)
than first 2 rows
Runs counter to main-
group elements
Due to outer e-’s being
held more tightly
11. PHYSICAL PROPERTIES OF METALS
1. Efficient conduction of heat and electricity
2. Malleability (they can be hammered into thin sheets)
3. Ductility (they can be pulled into wires)
4. A lustrous (shiny) appearance
5. All transition elements are metal at room temperature
except mercury which is liquid at room tempeture.
Platinum Sliver Gold Copper
12. ALLOYS
Alloys are a mixture of
metals to improve strength.
Examples of alloys include:
Gold jewelry (Au and Ag)
Bronze – Cu and Sn
Brass – Cu and Zn
Sterling silver – Cu and
Ag
13. MAGNETIC PROPERTIES
• Although an electron behaves like a tiny
magnet, two electrons that are opposite in spin
cancel each other. Only atoms with unpaired
electrons exhibit magnetic susceptibility
• A paramagnetic substance is one that is weakly
attracted by a magnetic field, usually the result
of unpaired electrons.
• A diamagnetic substance is not attracted by a
magnetic field generally because it has only
paired electrons.
14. COLOR OF COMPLEX IONS
The color wheel:
absorption of color
appears as
complementary color
Color in causes lower d-
orbital e- to go up to
higher d-orbital state
Specific wavelength of
light kicked out
The complement of
color absorbed
Colorless complexes are
either d0 or d10
Don’t have d-orbital e-
’s to move up
15. e- in partially filled d sublevel absorbs
visible light
moves to slightly higher energy d orbital
18. TRANSITION METALS
Elements in groups
3-12
Less reactive harder
metals
Includes metals used
in jewelry and
construction.
Metals used “as
metal.”
19. BRONZE
Copper alloys containing tin, lead,
aluminum, silicon and
nickel are classified as bronzes.
Cu-Sn Bronze is one of the earliest
alloy to be discovered as Cu ores
invariably contain Sn.
Stronger than brasses with good
corrosion and tensile
properties; can be cast, hot worked
and cold worked.
Wide range of applications: ancient
Chinese cast artifacts,
skateboard ball bearings, surgical
and dental instruments.
20. COPPER
The second largest use of Cu
is probably in coins.
The U.S. nickel is actually 75%
copper. The dime, quarter,
and half dollar coins contain
91.67% copper and the Susan B
Anthony dollar is 87.5% copper.
The various Euro coins are
made of Cu-Ni, Cu-Zn-Ni or
Cu-Al-Zn- Sn alloys.
21. APPLICATIONS OF STAINLESS
STEELS
•Stainless steels - A group of steels
that contain at least 11% Cr.
Exhibits extraordinary corrosion
resistance due to formation of a
very thin layer of Cr2O3 on the
surface.
Categories of stainless steels:
Ferrite Stainless Steels – Composed
of ferrite (BCC)
Martens tic Stainless Steels – Can be
heat treated.
Austenitic Stainless Steels –
Austenite ( ) phase field is extended
to room temperature. Most corrosion
resistant.
Duplex Stainless Steels – Ferrite +
Austenite
22. Biological Importance of Iron
Plays a central
role in almost all
living cells.
Component of
hemoglobin and
myoglobin.
Involved in the
electron-transport
chain.