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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
Name two elements you would expect to show chemical reactions similar to magnesium. What is the basis for your choice?
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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−
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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?
Compare and contrast the arrangement of elements in Mendeleev’s periodic Table and the Modern Periodic Table.
How does the metallic character of elements in Modern Periodic Table vary on moving from left to right in a period, and (ii) down a group?Give reason to justify your answer.
The atomic particle whose number in the atoms of an element always remains the same and which forms the real basis for the modern classification of elements is:
(a) electron
(b) proton
(c) neutron
(d) meson
Consider the following elements:
Na, Ca, Al, K, Mg, Li
Which of these elements belong to the same period of the periodic table?
Consider the following elements:
Ca, Cl, Na, I, Li, Ba, Sr, K, Br
Separate these elements into three groups (families) of similar properties. State one property in each case on the basis of which you have made your choice.
How would the tendency to gain electrons change on moving from left to right in a period of the periodic table?
What is the fundamental difference in the electron configurations between the group 1 and group 2 elements?
What is the usual number of valence electrons and valency of group 18 elements of the periodic table?
(b) What is the number of elements is 3rd period, the modern periodic table?
What is a group in the periodic table?
How many groups and periods does the modern periodic table have?
Name two elements in Inert gas.
What do you understand by typical elements?
Name the metals in the first twenty elements.
Name the type of elements which have two outermost shell incomplete.
How does the electronic configuration of an atom relate to its position in the modern periodic table?
Fill in the blank:
The horizontal rows in the periodic table are called _____________.
Define the atomic size.
Give the symbol and valency of the following element and radical.
Sodium
Give the symbol and valency of the following element and radical.
Zinc
Give the symbol and valency of the following element and radical.
Bicarbonate
Give the symbol and valency of the following element and radical.
Nitrate
Give the chemical formula of sodium bicarbonate
State the number of elements in Period 3 of the Periodic Table.
Find the odd one out and give its explanation.
Answer the following question in one sentence.
The modern periodic table is divided into which blocks?
Elements in the modern periodic table are arranged in ______groups and______ periods.
Element ‘X’ forms a chloride with the formula XCl2, which is solid with a high melting point. X would most likely be in the same group of the periodic table as: ______
The longest period of the Modern Periodic Table is period.
Which of the following elements does not 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:
E and B
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.
Name two elements that you would expect to show chemical reactions similar to calcium. What is the basis of your choice?
Name the non-metals in the first twenty elements.
Answer the following in respect of element \[\ce{_16^32S}\].
Give its electronic configuration.
