Mass Number
Mass Number
Mass Number: It is defined as the sum of number of protons and neutrons in the nucleus of an atom. Protons and neutrons together are called as nucleons. Mass number is denoted by A. Mass number (A) = Number of protons + number of neutrons. Eg: He, Li, At. mass = 4 and 7 for He and Li respectively.
Number of neutrons = Mass number - atomic number
Atomic number = Number of protonsMass number is written as a superscript towards the left of the symbol. In the notation for an atom, the atomic number, mass and symbol of the element are to be written as:
Here, the mass number of helium, lithium, sodium are 1, 7, 23 respectively.
If atomic number and mass number of an element are 11 and 23 respectively, What will be the number of neutrons present in it? | |||
| Right Option : B | |||
| View Explanation | |||
Identify the number of neutrons present in a pair of elements with atomic numbers 20 and 13, if their mass numbers are 40 and 27, respectively: | |||
| Right Option : D | |||
| View Explanation | |||
The ratio between the neutrons in C and Si with respcet to atomic masses 12 and 28 is _____________ | |||
| Right Option : C | |||
| View Explanation | |||
Students / Parents Reviews [10]
One of the best institutes to develope a child interest in studies.Provides SST and English knowledge also unlike other institutes. Teachers are co operative and friendly online tests andPPT develope practical knowledge also.
Aman Kumar Shrivastava
10thIt has a great methodology. Students here can get analysis to their test quickly.We can learn easily through PPTs and the testing methods are good. We know that where we have to practice
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Eshan Arora
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Om Umang
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Shivam Rana
7thAbhyas Methodology is very good. It is based on according to student and each child manages accordingly to its properly. Methodology has improved the abilities of students to shine them in future.
Manish Kumar
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Hiya Gupta
8thMy experience was very good with Abhyas academy. I am studying here from 6th class and I am satisfied by its results in my life. I improved a lot here ahead of school syllabus.
Ayan Ghosh
8thI have spent a wonderful time in Abhyas academy. It has made my reasoning more apt, English more stronger and Maths an interesting subject for me. It has given me a habbit of self studying
Yatharthi Sharma
10thIt was a good experience with Abhyas Academy. I even faced problems in starting but slowly and steadily overcomed. Especially reasoning classes helped me a lot.
