Question

Why are the lanthanoid elements not found in nature in their elemental forms?

a. Lack of reactivity
b. High reactivity with air and moisture
c. Radioactive nature
d. Inability to form compounds

Answer 1

The lanthanoid elements are not found in nature in their elemental forms due to their high reactivity with air and moisture.

Step-by-step explanation:

The lanthanoid elements, also known as the lanthanides, are not found in nature in their elemental forms primarily due to their high reactivity with air and moisture.

These elements react easily with oxygen and water, forming oxides and hydroxides.

For example, when exposed to air, lanthanoid elements react to form a oxide layer on their surfaces, which prevents further reaction with air.