1.
Lanthanide has elements with atomic numbers
Correct Answer
B. 57-71
Explanation
Lanthanide elements are a group of elements in the periodic table that have atomic numbers ranging from 57 to 71. These elements are also known as the rare earth elements and are characterized by their similar chemical properties and the filling of the 4f electron orbital. They are commonly used in various applications such as magnets, catalysts, and lighting.
2.
Actinide has elements with atomic numbers
Correct Answer
D. 89-103
Explanation
The correct answer is 89-103. Actinide elements are a series of elements in the periodic table with atomic numbers ranging from 89 to 103. These elements are all radioactive and have similar properties. They are located in the bottom two rows of the periodic table, below the lanthanide series. Actinide elements include uranium, plutonium, and americium, among others.
3.
What is the symbol of Cerium?
Correct Answer
A. Ce
Explanation
The symbol for Cerium is Ce.
4.
What is the smallest atomic radius of lanthanide?
Correct Answer
A. Tm3+
Explanation
The smallest atomic radius of lanthanides is generally found in ions with higher positive charges. Since Tm3+ has a higher positive charge compared to Tm2+ and Sm3+, it will have a smaller atomic radius. Therefore, Tm3+ is the correct answer.
5.
Which of these is not an actinide element?
Correct Answer
C. Potassium
Explanation
Potassium is not an actinide element. Actinide elements are a series of elements in the periodic table that follow actinium. They are all radioactive and have similar chemical properties. Protactinium, uranium, and neptunium are all actinide elements, but potassium is not. Potassium belongs to the alkali metal group and is not radioactive.
6.
What is the atomic number of Fermium?
Correct Answer
A. 100
Explanation
Fermium is a synthetic element with the symbol Fm and atomic number 100. It is named after Enrico Fermi, an Italian physicist. Therefore, the correct answer is 100.
7.
________ is the most stable ligand chelating a lanthanide.
Correct Answer
B. EDTA
Explanation
EDTA is the most stable ligand chelating a lanthanide because it forms strong coordination bonds with the metal ion. The ethylenediaminetetraacetic acid (EDTA) molecule has multiple donor atoms (nitrogen and oxygen) that can bind to the lanthanide ion, forming a stable complex. The chelation process involves the formation of multiple bonds between the ligand and the metal ion, increasing the stability of the complex. In contrast, water (H2O) and oxalate have fewer donor atoms and therefore form weaker coordination bonds with lanthanides. Hence, EDTA is the most stable ligand for chelating a lanthanide.
8.
Which of these lanthanides is used in MRI technology?
Correct Answer
D. None of these
Explanation
None of these lanthanides is used in MRI technology. MRI machines use a magnetic field and radio waves to generate detailed images of the body's internal structures. The lanthanides, including Ge (germanium), La (lanthanum), and Ce (cerium), do not have the necessary magnetic properties to be used in MRI technology. Instead, MRI machines typically use gadolinium, which is not listed as an option in this question.
9.
What is the symbol of Neodymium?
Correct Answer
B. Nd
Explanation
The symbol for Neodymium is Nd.
10.
The the coordination number of Ln[N(SiMe3)2]3 is
Correct Answer
C. 3
Explanation
The coordination number of a complex is the number of ligands attached to the central metal ion. In this case, the complex is Ln[N(SiMe3)2]3, where Ln represents a lanthanide metal ion. The ligand in this complex is N(SiMe3)2. Each lanthanide metal ion is surrounded by three ligands, resulting in a coordination number of 3.