1. Which of the following elements has the maximum number of valence electrons?
Answer:
Explanation:
Neon, being a noble gas, has a full valence shell with 8 electrons.
2. Which gas is produced when chlorine reacts with cold and dilute sodium hydroxide?
Answer:
Explanation:
Chlorine reacts with cold and dilute sodium hydroxide to produce sodium chlorate and chlorine gas.
3. What is the oxidation state of chlorine in KClO3?
Answer:
Explanation:
In KClO3, the oxidation state of chlorine is +5.
4. Which of the following is not a property of noble gases?
Answer:
Explanation:
Noble gases have low boiling points due to weak van der Waals forces.
5. Which p-block element exists as a diatomic molecule at room temperature?
Answer:
Explanation:
Chlorine exists as a diatomic molecule (Cl2) at room temperature.
6. Which of the following elements forms the most acidic oxide?
Answer:
Explanation:
Sulphur forms SO3, which is the most acidic oxide among the given options.
7. Which halogen is a liquid at room temperature?
Answer:
Explanation:
Bromine is a liquid at room temperature, while others are either gases or solids.
8. Which element of the 15th group forms only covalent compounds?
Answer:
Explanation:
Nitrogen, due to its small size, forms only covalent compounds.
9. The compound that does not contain a triple bond is:
Answer:
Explanation:
Oxygen (O2) contains a double bond between the two oxygen atoms.
10. The most electronegative element of the periodic table belongs to the:
Answer:
Explanation:
Fluorine, the most electronegative element, belongs to the p-block.
11. The compound in which nitrogen exhibits the highest oxidation state is:
Answer:
Explanation:
In N2O5, nitrogen exhibits an oxidation state of +5.
12. Among the following, the element with the smallest atomic size is:
Answer:
Explanation:
As we move down a group, atomic size increases. Thus, aluminum has the smallest atomic size.
13. Which of the following is a noble gas?
Answer:
Explanation:
All listed options are noble gases.
14. The ability of an atom in a molecule to attract shared electrons to itself is called:
Answer:
Explanation:
Electronegativity is the ability of an atom to attract shared electrons to itself.
15. Which of the following oxides is amphoteric in nature?
Answer:
Explanation:
Aluminum oxide (Al2O3) shows both acidic and basic properties, making it amphoteric.
16. Which of the following is not an interhalogen compound?
Answer:
Explanation:
F2O is an oxide of fluorine and not an interhalogen compound.
17. Which of the following elements does not exhibit allotropy?
Answer:
Explanation:
Neon, being a noble gas, does not exhibit allotropy.
18. Among the halogens, which has the highest atomic radius?
Answer:
Explanation:
Atomic radius increases down a group; iodine, being at the bottom of the halogens, has the largest atomic radius.
19. Which of the following elements is used in photoelectric cells?
Answer:
Explanation:
Selenium is used in photoelectric cells due to its ability to convert light energy into electrical energy.
20. Which of the following compounds is used as a refrigerant?
Answer:
Explanation:
CCl2F2, also known as Freon, is commonly used as a refrigerant in air conditioners and refrigerators.