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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
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?
Why do all the elements of the same group have similar properties?
Name the scientist who first of all showed that atomic number of an element is a more fundamental property than its atomic mass.
Fill in the following blank with suitable word:
Group 1 elements are called ...............
Fill in the following blank with suitable word:
Group 17 elements are known as ...............
How many periods and groups are there in the long form of periodic table?
Give two example of group 1 elements.
How were the positions of isotopes of an element decided in the modern periodic table?
How were the positions of cobalt and nickel resolved in the modern periodic table?
where should hydrogen be placed in the modern periodic table? Give reason for your answer.
The modern periodic table was prepared by ______.
State whether the following statement is true or false:
On going down in a group of the periodic table, the number of valence electrons increases.
What is a period in a periodic table?
On the basis of electronic configuration, how will you identify the first element of a period?
What happens to the number of valence electrons in the atoms of elements as we go down in a group of the periodic table?
Explain why, the first period of the periodic table has only two elements whereas second period has eight elements
In what respects do the properties of group 1 elements differ from those of group 17 elements? Explain with examples by taking one element from each group.
Name the type of elements which have outermost shell complete.
Arrange the elements of second and third periods in increasing order of their atomic size.
Third Period.
Write the number of protons, neutrons and electronic configuration of \[\ce{_19^39K, _15^31P}\]. Also state their position in periodic table.
Name an alkali metal in period 3 and halogen in period 2.
How many periods and groups are there in the modern periodic table?
How does number of (i) valence electrons (ii) valency; vary on moving from left to right in the second period of a periodic table?
The horizontal rows in a periodic table are called _____.
Name the following:
The group of the Modern Periodic Table to which calcium [Ca2+] belongs.
Right or wrong sentence.
To the left of the zig-zag line in the periodic table are the metal elements.
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.
Noble gases belong to______ group of the periodic table.
The amount of energy released when one or more electrons is added to the neutral atom is ______
Which of the following elements does not lose an electron easily?
The maximum number of electrons that can be accommodated in s, p,d, and f subshells are ______.
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
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 |
Which of the element is a Metalloid?
Define periods of modern periodic table.
An element with atomic number ______ will form a basic oxide.
Name the following metal:
A metal present in period 3, group 1 of the periodic table.
