Tiêu đề Advanced series 8th class Chemistry- Solutions.pdf ✅

Class 8 – Chemistry | A -8 Atoms and Molecules 1 1. Atoms and Molecules Solutions LEVEL-I 1. Correct option: (B) J.J.Bezelius was the scientist who suggested a method of representing elements using the English letters(capital as well as small) 2. Correct option: (D) The symbol C stands for the element Carbon. It is derived from the English name of the element and the symbol is first letter of the name. 3. Correct option: (C) Latin name of Hg is Hydrargyrum, in Greek Hydro means water and argyros means silver.Hg is a heavy silvery d-block element. 4. Correct option: (A) Mendelevium is the element that named after the name of the scientist Mendeleev (some elements are named after the names of the scientists.) 5. Correct option: (D) Neptunium is the element that named after the planet name in the following elements. 6. Correct option: (A) Germanium is the element of the following elements named after the country’s name. 7. Correct option: (C) Atomic weight of a substance can be expressed in both gram atomic weight and gram atom. 8. Correct option: (A) We know relative atomic mass of O atom =Mass of one O atom/one twelve th of mass of C-12 isotope. =16amu/1amu =16(amu s got cancelled) 9. Correct option: (D) Chlorine molecule exist as Cl2, Gram molecular weight of chlorine is =2*atomic mass of Cl =2*35.5g =71.0g 10. Correct option: (B) The molar mass of H=H2=2*atomic mass of H =2*1.008g =2.016g 11. Correct option: (A) One mole of molecules of Oxygen means, it contains 6.023*1023 molecules of Oxygen.