Last seen: Jan 25, 2021
Molecular mass of H2O = (2 x 1) + (16) = 2 + 16 = 18 u
The Avogadro’s constant (6.022 x 1023) is defined as the number of atoms that are present in exactly 12 g of carbon-12.
Ammonium sulphate NH4+ SO42- Chemical formula → (NH4)2SO4.
Cations are positively charged ion. Anions are negatively charged ion.
Cation → Na+ Anion → Cl–
Charged atom is called as an ion. The ion can be positively charged called cation or negatively charged called anion.
The atomicity of phosphorus is P4 i.e., 4. The atomicity of nitrogen is N2 i.e., 2.
Atoms exist in the form of atom, molecule or ions.
The sum of the atomic masses of all the atoms in a molecule of the substance is expressed in atomic mass unit. E.g., H2O = 1 x 2 + 16 = 18 amu
The number of atoms constituting a molecule is known as its atomicity.
The smallest particle of an element or compound which can exist independently is called molecule.
The smallest particle of matter, which can take part in a chemical reaction is called atom.
John Dalton coined the term atom.
In a chemical substance the elements are always present in definite proportions by mass. E.g., In water, the ratio of the mass of hydrogen to the ma...
In a chemical reaction mass can neither be created nor destroyed. E.g., 2Na + Cl2 → 2NaCl 2 x 23 + 2 x 35.5 → 2(23 + 35.5)
(c) 6.022 x 1023 atoms of C = 24 g of carbon
(c) Atoms of same elements can combine in only one ratio to produce more than one compound.
The formula of ethanol is C2H5-OH. Its molecular mass is 46 u.