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प्रश्न
An element A has 2 electrons in its fourth shell. State:
its atomic number
उत्तर
Its atomic number is 20.
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संबंधित प्रश्न
Complete the table:
|
Atomic number |
Element |
Electronic configuration |
Select an element of the same group |
|
11 |
Sodium |
|
(Ca/N/K)… |
|
15 |
Phosphorus |
|
(Ba/N/Rb)… |
|
16 |
Sulphur |
|
(F/Cl/O)… |
|
9 |
Fluorine |
|
(Ca/Cl/K)… |
Relative atomic mass of a light element up to calcium is approximately ______ its atomic number.
What is meant by ‘period number’. What does it signify?
Give a reason for the following:
Properties of elements are periodic functions of their atomic numbers and not atomic weights.
In Modern Periodic Table the number of columns and periods are respectively _______ and _______.
Modern periodic law states that the physical and chemical properties of elements are the periodic functions of their ______.
State whether true or false. If false, correct the statement.
Newlands’ periodic table is based on atomic masses of elements and modern periodic table is based on atomic number of elements.
State modern periodic law.
The basis of modern periodic law is ______.
| Group in the modern periodic table | Families |
| 1 | ______ |
| ______ | Transition metals |
| ______ | Boron family |
| 15 | ______ |
| 17 | ______ |
