Chapter 24 Transition elements

Question 1

what’s the electronic configuration for Sc? 21e-

Answer 1

1s²2s²2p⁶3s²3p⁶ 3d¹4s²

Question 2

what’s the electronic configuration of Cr? 24e-

Answer 2

1s²2s²2p⁶3s²3p⁶ 3d⁵4s¹

Question 3

what’s the electronic configuration of copper? 29e-

Answer 3

1s²2s² 2p⁶3s²3p⁶3d¹⁰4s¹

Question 4

what is the electronic configuration of Fe? 26e-

Answer 4

1s²2s²2p⁶3s²3p⁶3d⁶4s²

Question 5

what is the electronic configuration of Fe²⁺? 26e- when element.

Answer 5

1s²2s²2p⁶3s²3p⁶3d⁶

Question 6

what is the electronic configuration of Fe³⁺? 26e- when element.

Answer 6

1s²2s²2p⁶3s²3p⁶3d⁵

Question 7

what two elements have a special case of electronic configuration and why?

Answer 7

Copper and Chromium

-they place e- singly up until the 3d orbital where 4s fills WITH ONE e-before 3d, this is due to 3d⁵ and 3d¹⁰ giving additional stability

Question 8

define a transition metal.

Answer 8

-d-block elements that form at least one ion with a partially filled d-orbital

Question 9

what two elements are not classified as transition elements even though they are d-block elements?

Answer 9

SCANDIUM and ZINC

Question 10

why is scandium not a transition element?

Answer 10

Sc - 1s²2s²2p⁶3s²3p⁶3d¹4s²

Sc³⁺ - 1s²2s²2p⁶3s²3p⁶

Sc only has one ion Sc³⁺ this ion doesn’t have any electrons in the d-sub shell.

Question 11

why is zinc not a transition element?

Answer 11

Zn - 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²

Zn²⁺ - 1s²2s²2p⁶3s²3p⁶3d¹⁰

Zincs only ion Zn²⁺ does not have a partially filled sub-shell.

Question 12

what are three main properties of transition metals?

Answer 12

• they form compounds in which the tm has different oxidation states
  e. g. iron(III)chloride and iron(II) chloride
• they form coloured compounds
• the elements and its compounds can act as catalysts

Question 13

State two examples of transition metals acting as catalysts.

Answer 13

• Cu²⁺ for the reaction of zinc with acids
• MnO₂ for the decomposition of H₂O₂

Question 14

define ligand.

Answer 14

-an atom, ion or molecule which can form dative covalent bonds by donating a pair of e- to a metal ion

Question 15

define a monodentate