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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
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?
Nitrogen (atomic number 7) and phosphorus (atomic number 15) belong to group 15 of the Periodic Table. Write the electronic configuration of these two elements. Which of these will be more electronegative? Why?
How does the electronic configuration of an atom relate to its position in the Modern Periodic Table?
What is periodicity in properties of elements with reference to the Modern Periodic Table?
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 ...............
What is meant by a period, in a periodic table?
Give two example of group 17 elements.
Which of the following statement is correct in regard to the classification of elements?
(a) Elements in modern periodic table are arranged on the basis of increasing atomic masses.
(b) Elements in Mendeleev's periodic table are arranged on the basis of increasing atomic numbers.
(c) In modern periodic table, the element nickel of lower atomic mass is kept before the element cobalt of higher atomic mass.
(d) In modern periodic table, the isotopes of chlorine having different atomic masses are kept in the same group.
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 lose electrons change as we go from left to right across a period of the periodic table?
How does the chemical reactivity of the halogens vary on going in group 17 of the periodic table?
Explain why All the elements of a group have similar chemical properties.
State how the valency of elements varies in a period of the periodic table?
Helium and neon are unreactive gases. What, if anything, do their atoms have in common?
The atomic numbers of the three elements X, Y and Z are 2, 6 and 10 respectively.
(i) Which two elements belong to the same group?
(ii) Which two elements belong to the same period?
Give reasons for your choice.
Give the group number of following elements present in periodic table
Name the type of elements which have outermost shell incomplete.
Fill in the blank:
The horizontal rows in the periodic table are called _____________.
An element barium has the atomic number 56. Look up its position in the periodic table and answer the following question.
Is it larger or smaller than caesium (Cs)?
The electronic configuration of an element T is 2, 8, 8, 1.
What is the period number of T?
What would be the correct order if Zn, Fe, Al and Cu are arranged in increasing order of reactivity?
What is the number of elements in the 1st period?
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
Give the symbol and valency of the following element and radical.
Potassium
State the number of elements in Period 1 of the Periodic Table.
Which of the following statements about the Modern periodic table is correct?
Mendeleev's periodic table : atomic mass : : Modern periodic table : _______
State whether true or false. If false, correct the statement.
Lanthanides and actinides are kept at the bottom of the periodic table because they resemble each other but they do not resemble with any other group elements.
On moving from left to right in a period in the periodic table, the size of the atom ______
In the modern periodic table, elements are arranged according to their ______
Where would you locate the element with electronic configuration 2,8 in the Modern Periodic Table?
If an element X is placed in group 14, what will be the formula and the nature of bonding of its chloride?
Arrange the following elements in the increasing order of their metallic character
| Mg, | Ca, | K, | Ge, | Ga |
Group 16 elements are collectively called as ______.
An element has the atomic number 12.
- Write the electric configuration.
- To which group and period does it belong.
Define periods of modern periodic table.
Name the non-metals in the first twenty elements.
An element has 2 electrons in its N shell.
Is it a metal or a non-metal?
