Answer:
false, Potassium and fluorine are not halogens.
only fluorine here is halogen.
potassium is an alkali earth metal it doesn't comes under category of halogens, but fluorine
is a non metal which comes under halogen family.
Answer:
more electron deficient
Explanation:
The nitro group is an electron withdrawing group. It withdraws electrons from the pyridine ring by resonance.
This electron withdrawal by resonance makes the pyridine ring less electron rich or more electron deficient.
Hence, the nitro group makes the pyrinde ring more electron deficient
Answer:

Explanation:
2C₄H₁₀ + 13O₂ ⟶ 8CO₂ + 10H₂O
n/mol: 4.3
13 mol of O₂ react with 2 mol of 2C₄H₁₀

Answer:
Hydrogen is an element
Explanation:
Hydrogen is an element with only hydrogen atoms, whereas air, carbon dioxide, and water are all made up of multiple elements with different types of atoms.