Last seen: Nov 14, 2021
Correct answer is (b) 10-7 nm
Correct answer is (d) Krypton and sulphur
Correct answer is (a) Proust
Correct answer is (c) 2.5g and 1.1g
Correct answer is (c) Phosphorus
Correct answer is (c) Lavoisier
Correct answer is (c) Kalium
Correct answer is (a) Helium
Correct answer is (d) John Dalton
Correct answer: (c) NaH + H2O → NaOH + H2 Explanation: (a) and (b) are disproportionation reactions. (c) is an oxidation reaction. 2H- → H2 + 2e...
Correct answer: (d) +6 Explanation: Xe = 53.5 % ∴ F = 46.5% Relative number of atoms Xe = = 0.4 and F = = 2.4 Simple ratio Xe = 1 and F ...
Correct answer: (d) NO3- is reduced in preference to hydronium ion Explanation: Zinc gives H2 gas with dil H2SO4/HCl but not with HNO3 because in ...
Correct answer: (a) CrO42- → Cr2O72- Explanation: O. N. of Cr on both sides is + 6.
Correct answer: d) Zn + 2HCl → ZnCl2 + H2 Explanation: (a) and (b) are neutralisation reactions. The oxidation state of Cu is +2 in both reactant ...
Correct answer is (a) Sodium
Correct answer is (b) Hg
Correct answer is (d) 3, 8, 4 and 1
(a) One atomic mass unit is defined as exactly one-twelfth the mass of an atom of carbon-12. Its symbol is ‘u’. (b) The atomic mass of an element i...
(a) Atoms are building block of all matter. They are the smallest particle of elements that can take part in a chemical reaction. They exist in combin...
(a) A symbol of an element is the short form used to represent an individual element or the atoms of the elements. They are commonly used to designate...