Transition metal electronic configurations

Question 1

a transition metal is

Answer 1

an element that forms one or more stable ions with incompletely filled d-orbitals

“transition metals are d-block elements that form on ore more stable ion with incompletely filled d orbitals”

Question 2

characteristics of transition metals are:

6 items

Answer 2

• hard solids
• high melting points
• can act as catalysts
• form coloured ions and compounds
• form ions with different oxidation numbers
• form ion with incompletely-filled d orbitals

Question 3

of the 10 elements in period 4 between group 2 and 3, only…….are transition metals with …………………not being classed as transition metals because:

Answer 3

only 8 are TM

scandium and zinc are not because they only form one ion and their compounds are not coloured

Question 4

the ……….orbital is of lower energy than the……..orbital meaning it is ……………….

Answer 4

4s is of lower energy than 3d, so fills first

Question 5

d orbitals hold up to………….e-

Answer 5

10 e-

Question 6

chromium and copper have irregular electronic configurations because:

Answer 6

it is more stable to half fill the 4s and 3d orbitals than to fill the 4s orbital completely and have only 4 e- in the 3d orbitals

Question 7

scandium and zinc only form one ion each because:

Answer 7

scandium (Sc) forms the Sc3+ ion by losing both its 4s e- and its 3d e-
zinc (Zn) forms the Zn2+ ion by losing both its 4s e- but none of its 3d e-, so neither have an incompletely filled d orbital

Question 8

the other 8 elements lose their……………..e- before their…………..e- meaning……………………..

Answer 8

lose their 4s e- before losing their 3d e- so have an incompletely filled d ortbial
each element can also lose a variable amount of electrons so form ions with different oxidation numbers

Question 9

ions with higher oxidation numbers usually form with

Answer 9

an electronegative element, such as oxygen

Question 10

the common oxidation numbers of the following are:
Ti
V
Cr
Mn
Fe
Co
Ni
Cu

also explain the pattern

Answer 10

the common oxidation numbers of the following are:
Ti  → Ti2O3 (+3) → TiCl4 (+4)
V → V2+ → VCl3 (3+) → V4+ → V2O5 (5+)
Cr → CrCl3 (3+) → K2CrO4 (6+)
Mn → MnCl2 (Mn2+ → MnO2 (4+) → KMnO4 (7+)
Fe → FeCl2 (2+) → Fe2O3 (3+)
Co → CoSO4 (2+) → CoCl3 (3+)
Ni → NiSO4 (2+)
Cu → Cu2O (+1) → CuSO4 (2+)

from Ti → Mn, the highest oxidation increases from 4+ to 7+ as all the 4s and 3d electrons become involved in bonding.
from Fe to Cu, the increasing nuclear charge means that the electrons are attracted more strongly and are less likely to be involved in bonding, so higher oxidation numbers are less common