The common name of sodium hydroxide is: MCQ with Answer and Explanation

Explanation:
Isobars are atoms of different elements with the same mass number but different atomic numbers. ⁴⁰Ar (atomic number 18) and ⁴⁰Ca (atomic number 20) both have mass number 40. Options A and D are isotopes (same element, different mass number). Option C are isotopes of hydrogen. Isobars have different chemical properties because of different proton numbers. Example: ¹⁴C and ¹⁴N.

Explanation:
In diamond, each carbon is sp³ hybridized and forms four covalent bonds, using all valence electrons. There are no delocalized electrons; thus it cannot conduct electricity. Graphite, with sp² hybridization, has one delocalized electron per carbon, making it a conductor. Diamond is an electrical insulator but excellent thermal conductor.

Explanation:
The thermite process involves the reduction of a metal oxide by aluminum powder, which is highly exothermic. It is used to extract metals like chromium, manganese, and iron from their oxides (e.g., Cr2O3 + 2Al -> 2Cr + Al2O3). It is also practically used for welding iron railway tracks.