Please note that this trick only applies to first 20 elements, in the video mass number is discussed which is the sum of protons and neutrons and mass number is always a whole number never in decimals. Mass number should not be confused with atomic mass in amu.
For Hindi version please refer to the link below
पहले 20 तत्वों का परमाणु क्रमांक और द्रव्यमान संख्या याद रखने की ट्रिक | रसायन विज्ञान | ग्रेड 7-10
[ Ссылка ]
Learn All sciences with Kunal B Mehta @ Make Me Scientific
