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प्रश्न
Find the correlation:
Mendeleev’s periodic table : atomic mass : : Modern periodic table : _______
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उत्तर
Mendeleev’s periodic table : atomic mass : : Modern periodic table : atomic number
Explanation:
Mendeleev organised his periodic table based on the atomic mass of elements. In contrast, the modern periodic table is based on the atomic number (the number of protons), which Henry Moseley demonstrated to be a more fundamental property for predicting periodic trends in chemical behaviour.
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संबंधित प्रश्न
In the Modern Periodic Table, which are the metals among the first ten elements?
The position of three elements A, B and C in the Periodic Table are shown below –
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Group 16
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Group 17
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A
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B
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C
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(a) State whether A is a metal or non-metal.
(b) State whether C is more reactive or less reactive than A.
(c) Will C be larger or smaller in size than B?
(d) Which type of ion, cation or anion, will be formed by element A?
What is meant by a group, in a periodic table?
Give two example of group 18 elements.
What is the significance of atomic number in the modern classification of elements? Explain with the help of an example.
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.
Is it possible to have an element having atomic number 1.5 placed between hydrogen and helium?
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?
Explain why All the elements of a group have similar chemical properties.
What are the periods in a periodic table? Give two characteristics of each.
What are horizontal rows and vertical columns in a periodic table known as?
What do you understand by typical elements?
An element barium has the atomic number 56. Look up its position in the periodic table and answer the following question.
Is it larger or smaller than caesium (Cs)?
The electronic configuration of an element T is 2, 8, 8, 1.
What is the period number of T?
State the modern periodic law for classification of elements. How many (i) groups and (ii) periods are there in the modern periodic table?
Write a short note.
Position of isotopes in the Mendeleev’s and the modern periodic table.
State the modern periodic law.
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.
Sodium
Give the symbol and valency of the following element and radical.
Bicarbonate
Give the chemical formula of sodium bicarbonate
The groups 1 and 2 constitute the ______ block.
Find the odd one out and give its explanation.
Write an Explanation.
Period
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.
An element which is an essential constituent of all organic compounds belongs to
Which of the following elements would lose an electron easily?
Arrange the following elements in the increasing order of their metallic character
| Mg, | Ca, | K, | Ge, | Ga |
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
Explain giving reason why although the nuclear charge in atoms increases in moving from left to right in a period as well as in moving from top to bottom in a group in the Modern periodic table, but the size of the atoms does not vary similarly in both situations.
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 ______.
State the group and period, of the element having three shells with three electrons in valence shell.
What is the general name of the last elements of the Periodic Table?
Answer the following in respect of element \[\ce{_16^32S}\].
To which group and period does it belong?
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?
