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प्रश्न
Write a short note.
Structure of the modern periodic table.
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उत्तर
Structure of the modern periodic table:
Periodic Table: It is the table of chemical elements arranged in order of atomic number such that elements with similar atomic structure appear in the vertical columns. The Modern periodic law states that The chemical and physical properties of elements are a periodic function of their atomic numbers. The modern periodic table is based on modern periodic law.

Groups: There are 18 vertical columns in the periodic table. Each column is called a group. All elements in a group have similar chemical and physical properties because they have the same number of valence electrons.
Periods: In periodic table elements are arranged in a series of rows. Elements of the same period have the same number of electron shells.
Blocks: The table is divided into four blocks: s-block, p-block, d-block, and f-block, based on the type of orbital being filled. s- and p-blocks are called representative elements, d-block are transition metals, and f-block are inner transition elements (lanthanides and actinides).
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संबंधित प्रश्न
How does the electronic configuration of an atom relate to its position in the Modern Periodic Table?
Write the names given to the vertical columns and horizontal rows in the Modern Periodic Table. How does the metallic character of elements vary on moving down a vertical column? How does the size of atomic radius vary on moving left to right in a horizontal row? Give reason in support of your answer in the above two cases.
Fill in the following blank with suitable word:
The basis for modern periodic table is ...............
How many periods and groups are there in the long form of periodic table?
Give two example of group 18 elements.
Would you place the two isotopes of chlorine, CI-35 and CI-37 in different slots because of their different atomic masses or in the same slot because their chemical properties are the same? Justify your answer.
Which element has two shells, both of which are completely filled with electrons?
How does the chemical reactivity of the halogens vary on going in group 17 of the periodic table?
Explain why All the elements of a period have different chemical properties.
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?
State the term
The tabular arrangement of elements in horizontal rows and vertical columns _________
What are horizontal rows and vertical columns in a periodic table known as?
Name two elements in Inert gas.
Name two elements in each case:
Transition element
State the modern periodic law for classification of elements. How many (i) groups and (ii) periods are there in the modern periodic table?
What is the number of elements in the 3rd period, of the modern periodic table?
Give the symbol and valency of the following element and radical.
Aluminium
Give the symbol and valency of the following element and radical.
Magnesium
State the number of elements in Period 2 of the Periodic Table.
Which of the following statements about the Modern periodic table is correct?
Right or wrong sentence.
The modern periodic table has 1 to 7 periods.
Right or wrong sentence.
The modern periodic table shows the molecular masses of the elements in each frame.
In the modern periodic table, the positions of 1 to 20 elements are shown here. Identify the elements A and B. Write their atomic number.

An X element with atomic number 11 and Y element with atomic number 13 belongs to the third period in the modern periodic table. With this information, give the answers of the below questions.
- Which element has more metallic character from these two elements?
- What is the valency of each X and Y elements?
- Atom size of Y element is smaller than atom size of X element? Explain?
Noble gases belong to______ group of the periodic table.
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.
Identify gas A in the following experiment.

The inert gas which lies in the third period is ______
Which of the given elements A, B, C, D and E with atomic number 2, 3, 7, 10 and 30 respectively belong to the same period?
Which of the following elements would lose an electron easily?
The three elements A, B and C with similar properties have atomic masses X, Y and Z respectively. The mass of Y is approximately equal to the average mass of X and Z. What is such an arrangement of elements called as? Give one example of such a set of elements.
Arrange the following elements in the increasing order of their metallic character
| Mg, | Ca, | K, | Ge, | Ga |
______ group elements are called alkaline earth metals.
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
- Write the electronic configuration of element X, given by its symbol as under: \[\ce{^40_20 X}\]
- Determine its position in the modem periodic table.
- What is the nature of its oxide?
- Name one other element of its group.
Name the following metal:
A metal present in period 3, group 1 of the periodic table.
Give reason for the following:
Inert gases do not form ion.
A group of elements in the periodic table is given below (Boron is the first member of the group and Thallium is the last).
Boron, Aluminium, Gallium, Indium, Thallium
Answer the following question in relation to the above group of elements:
If the electronic configuration of aluminium is 2, 8, 3, how many electrons are there in the outer shell of thallium?
