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प्रश्न
Explain structure of modern periodic table in short.
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उत्तर
- The modern periodic table consists of seven horizontal rows called the periods and eighteen vertical columns called the groups.
- The arrangement of the periods and groups results in the formation of boxes, where each box corresponds to the position of an element.
- Atomic numbers are serially indicated in the upper part of these boxes.
- In addition to these seven rows, lanthanide and actinide series are shown separately at the bottom of the periodic table. The first row is lanthanide series and the second row is actinide series.
- There are 118 boxes in the periodic table including the two series. vi. The entire periodic table is divided into four blocks: s-block, p-block, d-block and f-block.
- s-block: contains group 1 and 2 elements
p-block: contains group 13 to 18 elements
d-block: contains group 3 to 12 elements (transition elements)
f-block: contains lanthanide and actinide series - A zig-zag line is drawn in the p-block of the periodic table. Metals lie on the left side while nonmetals lie on the right side of this line. Metalloids lie along the border of this line.
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संबंधित प्रश्न
Name two elements you would expect to show chemical reactions similar to magnesium. What is the basis for your choice?
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?
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?
Write the names given to the vertical columns and horizontal rows in the Modern Periodic Table. How does the metallic character of elements vary on moving down a vertical column? How does the size of atomic radius vary on moving left to right in a horizontal row? Give reason in support of your answer in the above two cases.
How does the tendency of elements to gain electrons change as we move from left to right in a period? State the reason of this change.
Fill in the following blank with suitable word:
Group 18 elements are called ...............
Give two example of group 1 elements.
Would you place the two isotopes of chlorine, CI-35 and CI-37 in different slots because of their different atomic masses or in the same slot because their chemical properties are the same? Justify your answer.
The three elements having chemical symbols of Si, B and Ge are:
(a) all metals
(b) all non-metals
(c) all metalloids
(d) Si is metalloid, B is metal and Ge is non-metal
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.
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?
On the basis of electronic configuration, how will you identify the first element of a period?
What is the number of elements is 1st period the modern periodic table?
(b) What is the number of elements is 3rd period, the modern periodic table?
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?
What are horizontal rows and vertical columns in a periodic table known as?
Name the type of elements which have two electrons in the outermost orbit.
Fill in the blank:
The horizontal rows in the periodic table are called _____________.
Give the symbol and valency of the following element and radical.
Bicarbonate
Give the symbol and valency of the following element and radical.
Sulphite
Give the chemical formula of sodium bicarbonate
Give the chemical formula of magnesium nitrate
Give the chemical formula of calcium phosphate
What are the elements.
What are the periods in a periodic table?
Group 1 and 2 : s block : : group 13 and 18 : _______
In the modern periodic table, the positions of 1 to 20 elements are shown here. Identify the elements A and B. Write their atomic number.
The scientist who propounded the modern periodic law is ______.
Which of the following elements would lose an electron easily?
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 same valency as Lithium.
Group 16 elements are collectively called as ______.
______ group elements are called alkaline earth metals.
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 |
Which of the element is a Noble gas?
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 ______.
Match the atomic number with the following:
A rare gas.
Match the atomic number with the following:
An element of group 2.
