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प्रश्न
Right or wrong sentence.
The modern periodic table shows the molecular masses of the elements in each frame.
पर्याय
Right
Wrong
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उत्तर
The given sentence is wrong.
Explanation:
The modern periodic table shows each element’s atomic number (and often its atomic/relative atomic mass) in the cell; it does not show a “molecular mass”. Elements have atomic masses; “molecular mass” refers to compounds (molecules).
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संबंधित प्रश्न
Compare and contrast the arrangement of elements in Mendeleev’s periodic Table and the Modern Periodic Table.
Write the merits of the modern periodic table over Mendeleev’s Periodic table
What is the significance of atomic number in the modern classification of elements? Explain with the help of an example.
Name the scientist who prepared modern periodic table.
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?
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 how the valency of elements varies in a period 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?
Explain why, the first period of the periodic table has only two elements whereas second period has eight elements
(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?
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?
Correct the statement.
Copper and zinc are representative elements.
Name two elements in Inert gas.
Name the type of elements which have two electrons in the outermost orbit.
Name an alkali metal in period 3 and halogen in period 2.
Answer the following question.
How it can be proved that the basic structure of the Modern Periodic Table is based on the electronic configuration of atoms of different elements?
Name the cation and the anion in the salt – calcium sulphate
Give the symbol and valency of the following element and radical.
Bicarbonate
Give the chemical formula of sodium hydroxide
Give the chemical formula of sodium nitrate
Give the chemical formula of sodium bicarbonate
Give the chemical formula of calcium phosphate
The groups 1 and 2 constitute the ______ block.
Find the correlation:
Mendeleev’s periodic table : atomic mass : : Modern periodic table : _______
Find the correlation:
Group 1 and 2 : s block : : group 13 and 18 : ______
Right or wrong sentence.
The K and L shells of the elements Na and Mg contain electrons.
Complete the following flow chart.
Noble gases belong to______ group of the periodic table.
State any five features of modern periodic table.
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 element which has the least tendency to lose electrons is ______
The element with atomic number 14 is hard and forms acidic oxide and a covalent halide. To which of the following categories does the element belong?
Which of the following elements would lose an electron easily?
Which of the following elements will form an acidic oxide?
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.
