Observe the following statements. Which is correct statement regarding...
The correct answer is option B
Ce shows +4 oxidation state in aq.solution
Ce (58) to lu (71)- lanthanide
Th (90) to Lr (103)- actinoids.
Observe the following statements. Which is correct statement regarding...
The correct statement regarding lanthanides is option 'B', which states that elements with atomic numbers 66 and 99 belong to the f-block.
Explanation:
Lanthanides are a series of chemical elements that belong to the f-block of the periodic table. The f-block consists of two separate rows, known as the lanthanides (elements with atomic numbers 57-71) and the actinides (elements with atomic numbers 89-103).
Elements with atomic numbers 66 and 99 fall within the range of the lanthanides.
Let's look at the atomic numbers of these elements:
- Element with atomic number 66: Dysprosium (Dy)
- Element with atomic number 99: Einsteinium (Es)
Both Dysprosium and Einsteinium are part of the lanthanides series.
The lanthanides are characterized by the filling of the 4f electron shell. They have similar chemical properties and are often referred to as rare earth elements. These elements have various applications in industries such as electronics, magnets, lighting, and catalysts.
Other statements mentioned in the question are incorrect:
a) Cerium shows 4 and 3 oxidation states: This statement is incorrect. Cerium is a lanthanide element and it exhibits oxidation states of +3 and +4, not just 4 and 3.
c) Lanthanides belong to the 3rd group and 7th period: This statement is incorrect. Lanthanides belong to the f-block and are not part of any specific group or period in the periodic table.
d) Monazite is the mineral that constitutes the major source of the lanthanides: This statement is incorrect. While monazite is a mineral that contains lanthanides, it is not the major source of these elements. Lanthanides are primarily obtained from ores such as bastnäsite and xenotime.