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प्रश्न
Fill in the blank:
The modern periodic table consists of ……………. periods.
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उत्तर
The modern periodic table consists of 7 periods.
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संबंधित प्रश्न
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?
In the Modern Periodic Table, calcium (atomic number 20) is surrounded by elements with atomic numbers 12, 19, 21, and 38. Which of these have physical and chemical properties resembling calcium?
What is meant by a group, in a periodic table?
How were the positions of cobalt and nickel resolved in the modern periodic table?
On which side of the periodic table will you find non-metals?
Explain why, the noble gases are placed in a separate group.
Name the scientist who prepared modern 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?
Explain why all the elements of a group have similar chemical properties.
Explain why all the elements of a period have different chemical properties.
What is the usual number of valence electrons and valency of group 18 elements of the periodic table?
What is the main characteristic of the last elements in the periods of the periodic table? What is the general name of such elements?
What is the number of elements is 1st period the modern periodic table?
What are the merits of the modern periodic table of elements?
Name two elements in each case:
Transition element
Name the type of elements which have outermost shell complete.
The electronic configuration of an element T is 2, 8, 8, 1.
What is the period number of T?
Give the symbol and valency of the following element and radical.
Calcium
Give the symbol and valency of the following element and radical.
Carbonate
State what is meant by the term chemical formula.
Give the chemical formula of sodium hydroxide
Give the chemical formula of calcium phosphate
Write an explanation.
Period
Distinguish between:
s-block - p-block
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 an 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.
______ and ______ are called inner transition elements.
Identify gas A in the following experiment.
In the modern periodic table, elements are arranged according to their ______
The elements A, B, C, D and E have atomic number 9, 11, 17, 12 and 13 respectively. Which pair of elements belong to the same group?
Which of the following elements will form an acidic oxide?
The three elements A, B and C with similar properties have atomic masses X, Y and Z respectively. The mass of Y is approximately equal to the average mass of X and Z. What is such an arrangement of elements called as? Give one example of such a set of elements.
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).
- Write the electronic configuration of element X, given by its symbol as under: \[\ce{^40_20 X}\]
- Determine its position in the modem periodic table.
- What is the nature of its oxide?
- Name one other element of its group.
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.
An element with atomic number ______ will form a basic oxide.
State the group and period, of the element having three shells with three electrons in valence shell.
An element has 2 electrons in its N shell.
Is it a metal or a non-metal?
