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Flashcards in f block Deck (16)
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1
Q

Which series has only one stable oxidation state?

A

Lanthanum

2
Q

Atomic size …………… from Lanthanum to Lutetium.

A

Atomic size decreases

3
Q

What is the predominant valency in the La series?

A

3+

4
Q

Pr,Nd,Tb,Dy in MO2 express what Ox.state?

A

4+

5
Q

When is Eu+ a strong reducing agent

A

When you go from +2 - +3

6
Q

Colour of Lanthanoid elements can be attributed to ….

A
  • the presence of f electrons
7
Q

There is irregularity in the IE3 values. Where can it be seen?

A

Especially low values of La,Gd,Lu.

8
Q

Elements in the beginning of the series behave like …….. ; elements lower behave like ……..

A
  • Ca

* Al

9
Q

Which element has a half life of 3 minutes?

A

Lawrencium

10
Q

Why can Ac elements participate more liberally in bond formation than La elements?

A

This is because the 5f orbitals are not as buried as the 4f orbital.

11
Q

Which is greater, Ac contraction or La contraction

A

Ac

12
Q

Why do the Ac elements have a great range of ox.states ?

A

This is because their 5f,6d and 7s orbitals are of comparable energies.

13
Q

Which acid reacts with all actinides?

A

Hcl

14
Q

Why are Ac elements coloured?

A

Due to:

  • Charge transfer
  • f-f transition
15
Q

Which compound is used in the pigment industry?

A

TiO

16
Q

What was the first synthetic element?

A

Tc