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प्रश्न
Write the merits of the modern periodic table over Mendeleev’s Periodic table
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उत्तर
1) Elements are arranged on the basis of increasing atomic number which is more fundamental.
2) Isotopes of an element can be placed along with parent element.
3) It explains periodicity of properties of elements configuration.
4) Lanthanides and actinides are placed separately.
5) Anomalous pairs of elements like Ar and K having same atomic mass could be justified
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संबंधित प्रश्न
State modern periodic law.
Fill in the following blank with suitable word:
The basis for modern periodic table is ...............
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 ...............
On which side of the periodic table will you find metals?
What is the name of those elements which divide metals and non-metals in the periodic table?
Consider the following elements:
Na, Ca, Al, K, Mg, Li
Which of these elements belong to the same period of the periodic table?
What is the major characteristic of the first elements in the periods of the periodic table? What is the general name of such elements?
What is the main characteristic of the last elements in the periods of the periodic table? What is the general name of such elements?
Name two elements in each case:
Transition element
Name the type of elements which have two outermost shell incomplete.
What is the main characteristic of the last element in each period of the periodic table?
Fill in the blank:
The horizontal rows in the periodic table are called _____________.
An element barium has atomic number 56. Look up its position in the periodic table and answer the following question.
What will be the formula of its phosphate?
The electronic configuration of an element T is 2, 8, 8, 1.
- What is the group number of T?
- What is the period number of T?
- How many valence electrons are there in an atom of T?
- What is the valency of T?
- Is it a metal or a non-metal?
Two elements P and Q belong to the same period of the modern periodic table and are in group 1 and group 2, respectively. Compare the following characteristics in the tabular form.
- Number of electrons in their atoms
- Their tendency to lose electrons
- Their metallic characters
- Formation of their oxides
- Formulae of their chlorides
Name the cation and the anion in the salt – calcium sulphate
Give the symbol and valency of the following element and radical.
Hydrogen
Give the symbol and valency of the following element and radical.
Sulphur [Sulphide]
Give the symbol and valency of the following element and radical.
Bisulphate
Give the symbol and valency of the following element and radical.
Sulphate
Give the chemical formula of magnesium nitrate
Distinguish between:
Group 17 - Group 18
State any five features of modern periodic table.
______ and ______ are called inner transition elements.
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: ______
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.
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 variable valency and is a member of the Oxygen family (group 16).
Explain the position of hydrogen in the 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
Give the criteria on the basis of which elements are placed (i) in a group and (ii) in a period in the modern periodic table. The atomic number of an element is 16. According to the criteria, in which group and period it should be placed?
An element belonging to 3d series of modern periodic table has spin magnetic moment = 5.92 B.M. in +3 oxidation state. The atomic number of elements are ______.
Select the appropriate options and complete the following paragraph:
(metals, non-metals, metalloids, four, seven, s-block, p-block, d-block, f-block).
On the basis of electronic configuration, elements in the modern periodic table are classified Into ______ blocks. Groups 1 and 2 elements are included in ______ and all these elements are metals. (except Hydrogen). Group 13 to 18 elements are included in ______. This block contains metals, non-metals and metalloids. Group 3 to 12 elements are included in ______ and all the elements are ______ elements shown at the bottom of the periodic table i.e. Lanthanides and Actinides constitute ______ and all these elements are metals.
State the group and period, of the element having three shells with three electrons in valence shell.
Name two elements that you would expect to show chemical reactions similar to calcium. What is the basis of your choice?
What is the general name of the last elements of the Periodic Table?
An element has 2 electrons in its N shell.
State its position in periodic table.
Give reason for the following:
Inert gases do not form ion.
