Question
Why does the melting point of the elements decrease down group 1?
A. Atomic mass increases
B. Number of electrons increases
C. Radius of metal ion increases
D. First ionization energy decreases
▶️Answer/Explanation
Markscheme: C
The correct answer is C. Radius of metal ion increases.
Down Group 1 (alkali metals), as you move from the top (e.g., lithium) to the bottom (e.g., cesium), the size of the atoms increases. This is due to the addition of new electron shells as you go down the group. As the atoms get larger, the outer electrons are farther from the nucleus, and the attractive forces between the electrons and the nucleus become weaker.
The weakening of these forces results in a decrease in the melting point down Group 1. The outer electrons are held less tightly by the nucleus, making it easier for the metal atoms to overcome the attractive forces and transition into the liquid phase.
So, the correct choice is C. Radius of metal ion increases.
Question
Which particles are present in the lattice of a metal?
A. Negative ions
B. Positive and negative ions
C. Positive ions
D. Molecules
Answer/Explanation
Markscheme
Examiners report
C
Question
Which metal has the strongest metallic bond?
A. Li
B. Na
C. K
D. Rb
Answer/Explanation
Markscheme
A
Examiners report
Question
Zinc metal contains metallic bonding. Which is the best description of a metallic bond?
A. The electrostatic attraction between a pair of electrons and positively charged nuclei.
B. The electrostatic attraction between oppositely charged ions.
C. The electrostatic attraction between a lattice of positive ions and delocalized electrons.
D. The bond formed when one atom provides both electrons in a shared pair.
Answer/Explanation
Markscheme
C
Question
Which metal has the strongest metallic bonding?
A. Na
B. Mg
C. Al
D. Ca
Answer/Explanation
Markscheme
C