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प्रश्न
From the symbol \[\ce{^4_2He}\] for the element helium, write down the mass number and the atomic number of the element.
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उत्तर
\[\ce{_{Atomic number} ^4_2He ^{mass number}}\]
- Mass number – 4
- Atomic number – 2
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संबंधित प्रश्न
In Milikan’s experiment, static electric charge on the oil drops has been obtained by shining X-rays. If the static electric charge on the oil drop is - 1.282 × 10-18C, calculate the number of electrons present on it.
The atom of an element is made up of 4 protons, 5 neutrons and 4 electrons. What is its atomic number and mass number?
WRITE SHORT ANSWER
Define the atomic mass number of an atom.
Define the term ‘mass number’ of an atom.
Draw the atomic diagram of the following element showing the distribution of – protons, neutrons and the electrons in the various shell of the atom.
Calcium – \[\ce{^40_20Ca}\]
[The upper number represent the – mass number and the lower number represent the – atomic number e.g. calcium – mass number = 40, atomic number = 20]
Differentiate mass number from atomic number.
Electrons revolve around the nucleus in definite open shells.
In a neutral atom number of protons is equal to the number of neutrons.
Match the following:
| Column A | Column B | ||
| 1. | K shell | a. | 8 |
| 2. | L shell | b. | 32 |
| 3. | M shell | c. | 2 |
| 4. | N shell | d. | 18 |
If M is the atomic mass and A is the mass number, then packing fraction is given by ______.
