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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?
What is periodicity in properties of elements with reference to the Modern Periodic Table?
Fill in the following blank with suitable word:
Group 17 elements are known as ...............
What is meant by a period, in a periodic table?
Is it possible to have an element having atomic number 1.5 placed between hydrogen and helium?
Which of the following statement about the modern periodic table is correct?
(a) It has 18 horizontal rows known as periods.
(b) It has 7 vertical columns known as periods.
(c) It has 18 vertical columns known as groups.
(d) It has 7 horizontal rows known as groups.
Which element has two shells, both of which are completely filled with electrons?
How does the chemical reactivity of alkali metals vary on going in group 1 of the periodic table?
What is the usual number of valence electrons in the atoms of the last element in a period?
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.
How do the atomic radii of elements change as we go from left to right in a period of the periodic table?
State how the valency of elements varies in a group of the periodic table?
What happens to the number of valence electrons in the atoms of elements as we go down in a group of the periodic table?
(b) What is the number of elements is 3rd period, the modern periodic table?
Helium and neon are unreactive gases. What, if anything, do their atoms have in common?
What are the periods in a periodic table? Give two characteristics of each.
Give the group number of following elements present in periodic table
State the term
The tabular arrangement of elements in horizontal rows and vertical columns _________
What do you understand by typical elements?
An element A has 2 electrons in its fourth shell. State its electronic configuration.
Name the cation and the anion in the salt – calcium sulphate
Give the symbol and valency of the following element and radical.
Sulphite
Give the chemical formula of ammonium sulphate
State what the group number in the Modern Periodic Table signifies. Give a reason why elements in the same group, have similar valency and similar chemical properties.
Which of the following statements about the Modern periodic table is correct?
What are groups and periods in the modern periodic table?
______ and ______ are called inner transition elements.
The longest period of the Modern Periodic Table is period.
If an element X is placed in group 14, what will be the formula and the nature of bonding of its chloride?
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.
Spot the error:
The elements of group 13 are called the carbon family.
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
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?
An element has 2 electrons in its N shell.
Is it a metal or a non-metal?
Match the atomic number with the following:
A rare gas.
Match the atomic number with the following:
An element of group 2.
