Question

write the Properties of Lanthanoids​

Answer 1

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i. Soft metals with silvery white colour and moderate densities of ~ 7 g cm^-3. Colour and brightness reduces on exposure to air

ii. Good conductors of heat and electricity.

iii. Except promethium (Pm), all are non- radioactive in nature.

iv. The atomic and ionic radii decrease from lanthanum (La) to lutetium (Lu). This is known as lanthanoid contraction.

v. Binding to water is common (i.e.) such that H_2O is often found in products when isolated from aqueous solutions.

vi. Coordination numbers usually are greater than 6, typically 8, 9,... (up to 12 found).

vii. The lanthanoides are strongly paramagnetic. Gadolinium becomes ferromagnetic below 16 °

C (Curie point). The other heavier lathanoids terbium, dysprosium, holmium, erbium, thulium, and ytterbium – become ferromagnetic at much lower temperatures.

viii. Magnetic and optical properties are largely independent of environment (similar spectra in gas/solution/solid).

Answer 2

Explanation:

Common Properties of the Lanthanides

Common Properties of the LanthanidesLanthanides share the following common properties: Silvery-white metals that tarnish when exposed to air, forming their oxides. Relatively soft metals. Hardness increases somewhat with higher atomic number.