Chromic acid and ammonia

Chromium sesquioxide and nitrogen

Chromium sesquioxide and ammonia

Chromic acid and nitrogen

Solution in test tube becomes green and lime water turns milky

Solution in test tube is colourless and lime water turns milky

Solution in test tube becomes green and lime water remains clear

Solution in test tube is colourless and lime water also remains clear

3d elements show more oxidation states than 4f series elements

The energy difference between 3d and 4f orbitals is very less

Europium (II) is more stable than Ce (II)

The paramagnetic character in 3d series elements increases from scandium to copper

4 to 2

6 to 4

7 to 2

7 to 4

In addition to the normal oxidation states, the zero oxidation state is also shown by these elements in complexes

In the highest oxidation states, the transition metals show basic character and form cationic complexes

In the highest oxidation states of the first five transition elements (Sc to Mn), all the 4s and 3d electrons are used for bonding

Once the d⁵ configuration is exceeded, the tendency to involve all the 3d electrons in bonding decreases