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प्रश्न
Explain the Mass number with example.
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उत्तर
The mass number of an element is equal to the sum of the number of protons and the number of neutrons present in it.
Example: Number of protons in carbon = 6
Number of neutrons = 6
Hence mass number = Number of protons + Number of neutrons
= 6 + 6
= 12
संबंधित प्रश्न
FILL IN THE BLANK
Rutherford won the Nobel Prize in 1908 for his investigations in the field of ......................
Fill in the following blanks in respect of an atom of an element
| No. of protons | No. of neutron | Mass number | Atomic number | No. of electrons | Symbol |
| 11 | 12 | ___________ | ___________ | ___________ | ________ |
(a) What is meant by (i) atomic number, and (ii) mass number, of an element? Explain with the help of an example.
(b) What is the relation between the atomic number and mass number of an element?
(c) If an element M has mass number 24 and atomic number 12, how many neutrons does its atom contain?
From the symbol `""_15^31"P"`, state :
(i) mass number of phosphorus,
(ii) atomic number of phosphorus, and
(iii) electron configuration of phosphorus.
What are orbits or shells of an atom?
Draw the structure of the following atoms showing the nucleus containing – protons, neutrons and the orbits with the respective electron:
Isotopes of hydrogen [11H, 21H, 31H]
An element ‘A’ has mass number 23 and atomic number 11. State the –
- no. of neutrons in its shell,
- electronic configuration of the element ‘A’.
Complete the following table.
| Atomic Number | Mass Number | Number of Neutrons | Number of Protons | Number of Electrons | Name of the Element |
| 9 | ______ | 10 | ______ | ______ | ______ |
| 16 | ______ | 16 | ______ | ______ | ______ |
| ______ | 24 | ______ | ______ | 12 | Magnesium |
| ______ | 2 | ______ | 1 | ______ | ______ |
| ______ | 1 | 0 | 1 | 1 | ______ |
What are nucleons? How many nucleons are present in Phosphorous? Draw its structure.
If M is the atomic mass and A is the mass number, then packing fraction is given by ______.
