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प्रश्न
Match the atomic numbers 4,8,10,15 and 19 with the following:
Element which can form trivalent ion
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उत्तर
Atomic number 15
Electronic configuration (15): 2,8,5
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संबंधित प्रश्न
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Atomic theory of matter was given by ..........................
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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 | ___________ | ___________ | ___________ | ________ |
The mass number of an element is 18. It contains 7 electrons. What is the number of protons and neutrons in it? What is the atomic number of the element?
The atom of an element X has 7 electrons in its M shell.
What is the atomic number of element X?
An atom of an element has two electrons in the M shell.
What is the (a) atomic number (b) number of protons in this element?
An element A atomic number 7 mass numbers 14
B electronic configuration 2,8,8
C electrons 13, neutrons 14
D Protons 18 neutrons 22
E Electronic configuration 2,8,8,1
State Valency of each element
An element A atomic number 7 mass numbers 14
B electronic configuration 2,8,8
C electrons 13, neutrons 14
D Protons 18 neutrons 22
E Electronic configuration 2,8,8,1
State (i) Valency of each element (ii) which one is a metal (iii) which is non-metal (iv) which is an inert gas
Draw the structure of the following atoms showing the nucleus containing – protons, neutrons and the orbits with the respective electron:
Sodium [At. no. = 11, Mass no. = 23]
Elements X, Y, Z have atomic numbers 6, 9 and 12 respectively. Which one:
- forms anion – negative ion;
- forms cation – positive ion;
- has 4 electrons in the outermost orbit. [Y, Z, X]
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 | ______ |
