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प्रश्न
Explain structure of modern periodic table in short.
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उत्तर
- The modern periodic table consists of seven horizontal rows called the periods and eighteen vertical columns called the groups.
- The arrangement of the periods and groups forms boxes, with each box corresponding to the position of an element.
- Atomic numbers are serially indicated in the upper part of these boxes.
- In addition to these seven rows, the lanthanide and actinide series are shown separately at the bottom of the periodic table. The first row is the lanthanide series, and the second row is the actinide series.
- There are 118 boxes in the periodic table, including the two series. vi. The entire periodic table is divided into four blocks: s-block, p-block, d-block and f-block.
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- s-block: contains group 1 and 2 elements
- p-block: contains groups 13 to 18 elements
- d-block: contains groups 3 to 12 elements (transition elements)
- f-block: contains the lanthanide and actinide series
- A zig-zag line is drawn in the p-block of the periodic table. Metals lie on the left side while nonmetals lie on the right side of this line. Metalloids lie along the border of this line.
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संबंधित प्रश्न
Fill in the blank:
The modern periodic table consists of ……………. periods.
In the Modern Periodic Table, calcium (atomic number 20) is surrounded by elements with atomic numbers 12, 19, 21, and 38. Which of these have physical and chemical properties resembling calcium?
What is meant by a period, in a periodic table?
Give two example of group 1 elements.
What is the significance of atomic number in the modern classification of elements? Explain with the help of an example.
How were the positions of cobalt and nickel resolved in the modern periodic table?
Explain why, the noble gases are placed in a separate group.
The modern periodic table was prepared by ______.
Which element has two shells, both of which are completely filled with electrons?
Give alongside is a part of the periodic table :
As we move horizontally from left to right:
| Li | Be | B | C | N | O | F | |
| Na | Mg | Al | Si | P | S | Cl |
(i) What happens to the metallic character of the elements?
(ii) What happens to the atomic size?
How would the tendency to gain electrons change on moving from left to right in a period of the periodic table?
What is a period in a periodic table?
What is the number of elements is 1st period the modern periodic table?
Consider the following elements:
20Ca, 8O, 18Ar, 16S, 4Be, 2He
Which of the above elements would you expect to be:
(i) very stable?
(ii) in group 2 of the periodic table?
(iii) in group 16 of the periodic table?
Correct the statement.
Copper and zinc are representative elements.
Name the type of elements which have two outermost shell incomplete.
Name an alkali metal in period 3 and halogen in period 2.
Write a short note.
Position of isotopes in the Mendeleev’s and the modern periodic table.
What is meant in the periodic table by a period?
What is the number of elements in the 3rd period, of the modern periodic table?
Name and state the following with reference to the elements of the first three periods of the periodic table.
A covalent compound formed by an element in period 2 and a halogen.
Give the symbol and valency of the following element and radical.
Sodium
Give the symbol and valency of the following element and radical.
Bisulphite
Give the chemical formula of sodium hydroxide
State the number of elements in Period 2 of the Periodic Table.
What are the elements.
Compare Modern Periodic Law with Mendeleev's Periodic Law.
Right or wrong sentence.
The K and L shells of the elements Na and Mg contain electrons.
State whether true or false. If false, correct the statement.
Lanthanides and actinides are kept at the bottom of the periodic table because they resemble each other but they do not resemble with any other group elements.
______ forms the basis of the modern periodic table.
In the modern periodic table, elements are arranged according to their ______
The longest period of the Modern Periodic Table is period.
Which one of the following elements exhibit maximum number of valence electrons?
Noble gases are placed in the ______ group in the modern periodic table.
Spot the error:
There are 5 periods and 17 groups in the modern periodic table.
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:
E and B
Give the criteria on the basis of which elements are placed (i) in a group and (ii) in a period in the modern periodic table. The atomic number of an element is 16. According to the criteria, in which group and period it should be placed?
Define groups of modern periodic table.
An element ‘M' has 50% of the electrons filled in the 3rd shell as in the 2nd shell. The atomic number of ‘M’ is ______.
