This set of Chemistry Multiple Choice Questions & Answers (MCQs) focuses on “Solid State Electrical Properties”.
1. Metals are good conductors of heat and electricity. This property is conferred by _______ bonds.
Explanation: Metallic bonds are formed between positive metal ions and the sea of delocalized electrons. This bond is stronger than covalent and ionic bonds. Due to the mobility of electrons, conduction of heat and electricity is feasible.
2. Which of the following properties holds true for a metalloid?
a) Poor conductors of heat and electricity
Explanation: Metalloids have properties intermediate to those of metals and non-metals. They are non-malleable, non-ductile and brittle. They are poor conductors of heat and electricity as compared to metals, but are better conductors than non-metals.
3. According to the band theory, increase in number of atoms participating in crystal formation leads to ________ in number of molecular orbitals containing electrons.
c) no change
d) either increase or decrease, depending upon the size of the atoms
Explanation: The band theory assumes that atomic orbitals of the atoms of the crystal combine to form molecular orbitals which are spread over the whole crystal structure. Hence, the number of atoms is directly proportional to the number of molecular orbitals formed.
4. For a metallic crystal, which band do the delocalized electrons occupy?
a) Conduction band
b) Valence band
c) Both, conduction and valence bands
d) There are no delocalized electrons
Explanation: A metallic crystal has valence electrons in the valence band and free moving, delocalized electrons in the conduction band. For a metal, these two bands are very close to each other.
5. A substance containing one band completely filled with electrons and other band completely empty, but with a possibility of the empty band becoming populated, behaves as a _________
d) metal and non-metal
Explanation: Semiconductors have completely filled valence bands and completely empty conduction bands. The energy gap between the two bands is relatively small and can be overcome by supplying heat, which excites some electrons to the conduction band, thus allowing the conduction of electricity.
6. Label the diagram correctly.
a) 1-Non metal, 2-Semiconductor, 3-Metal
b) 1-Semiconductor, 2-Non metal, 3-Metal
c) 1-Metal, 2-Semiconductor, 3-Non metal
d) 1-Metal, 2-Non metal, 3-Semiconductor
Explanation: Energy gap is very less (may even be absent) for metals, very huge for non metals and intermediate (small) for semiconductors.
Sanfoundry Global Education & Learning Series – Chemistry – Class 12.
To practice all areas of Chemistry, here is complete set of 1000+ Multiple Choice Questions and Answers.
- Get Free Certificate of Merit in Chemistry - Class 12
- Participate in Chemistry - Class 12 Certification Contest
- Become a Top Ranker in Chemistry - Class 12
- Take Chemistry - Class 12 Tests
- Chapterwise Practice Tests: Chapter 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
- Chapterwise Mock Tests: Chapter 1, 2, 3, 4, 5, 6, 7, 8, 9, 10