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प्रश्न
From the standpoint of atomic structure, what determines which elements will be the first and which the last in a period of the periodic table?
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उत्तर
- The periodic table is based on the atomic number of an element.
- Furthermore, the valence electrons determine their position in the group.
- Elements with one valence electron are classified as the first group, elements with two valence electrons as the second group, and vice versa.
- An element with 8 valence electrons belongs to the Periodic Table's last group (18th group) (excluding He).
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संबंधित प्रश्न
Name the metals in the first twenty elements.
In the Modern Periodic Table – atoms of all elements are arranged according to their increasing order of – atomic numbers. An atom of nitrogen has seven protons and seven electrons. State what would be its atomic number.
Give the symbol and valency of the following element and radical.
Hydrogen
Right or wrong sentence.
To the left of the zig-zag line in the periodic table are the metal elements.
On moving from left to right in a period in the periodic table, the size of the atom ______
The inert gas which lies in the third period is ______
Choose an element from period 3 of modern periodic table that matches the description given below in instance. Give a reason for your choice.
It has same valency as Lithium.
A part of modern periodic table is given below. On its basis, answer the following questions:
| Group No. → | 1 | 2 | 13 | 14 | 15 | 16 | 17 | 18 |
| Period ↓ | ||||||||
| 2 | A | B | ||||||
| 3 | E | D | F | C |
Write the molecular formula of the compound formed by the combination:
A and F
Name two elements that you would expect to show chemical reactions similar to calcium. What is the basis of your choice?
Match the atomic number with the following:
An element of group 2.
