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प्रश्न
Define periods of modern periodic table.
उत्तर
The horizontal rows are called periods. The periodic table contains seven periods.
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संबंधित प्रश्न
Fill in the blank:
The modern periodic table consists of ……………. periods.
In the Modern Periodic Table, which are the metals among the first ten elements?
Compare and contrast the arrangement of elements in Mendeleev’s periodic Table and the Modern Periodic Table.
How many rows and columns are there in the Modem Periodic Table?
Write the merits of the modern periodic table over Mendeleev’s Periodic table
What is meant by a group, in a periodic table?
Give two example of group 17 elements.
What is the significance of atomic number in the modern classification of elements? Explain with the help of an example.
How were the positions of cobalt and nickel resolved in the modern periodic table?
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.
Explain why, the first period of the periodic table has only two elements whereas second period has eight 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?
An element X belongs to 3rd period and group 2 of the periodic table. State:
(a) number of valence electrons
(b) valency
(c) metal or non-metal
(d) name of the element
What do you understand by typical elements?
Name the type of elements which have outermost shell incomplete.
Arrange the elements of second and third periods in increasing order of their atomic size.
Third Period.
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)?
State the main aim of classifying elements. Which is the more fundamental property of elements that is used in the development of Modern Periodic Table? Name and state the law based on this fundamental property. On which side of the periodic table one can find metals, non-metals and metalloids?
State the modern periodic law for classification of elements. How many (i) groups and (ii) periods are there in the modern periodic table?
An element E has following electronic configuration:
|
K |
L |
M |
|
2 |
8 |
6 |
(a) To which group of the periodic table does element E belong?
(b) To which period of the periodic table does element E belong?
(c) State the number of valence electrons present in element E.
(d) State the valency of the element E.
How will the tendency to gain electrons change as we go from left to right across a period? Why?
Write a short note.
Structure of the modern periodic table.
Answer the following question.
Define the atomic size. Give its unit of measurement. In the modern periodic table what trend is observed in the atomic radius in a group and a period and why is it so?
Give the symbol and valency of the following element and radical.
Aluminium
Give the symbol and valency of the following element and radical.
Nitrate
Give the chemical formula of magnesium nitrate
State the number of elements in Period 2 of the Periodic Table.
Which of the following statements about the Modern periodic table is correct?
Find the odd one out and give its explanation.
Position of A, B and C three elements is given in the table from the modern periodic table. Answer the following questions.
| Periods | Group 2 | Group 17 |
| 2 | ----- | A |
| 3 | B | ----- |
| 4 | ----- | C |
- What is A element metal or nonmetal?
- Which is the outermost orbit of element B?
- Identify C element and it's physical state.
Elements in the modern periodic table are arranged in ______groups and______ periods.
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.
______ is the longest period in the periodical table.
______ forms the basis of the modern periodic table.
The element which has the least tendency to lose electrons is ______
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).
Give reason for the following:
Inert gases do not form ion.
