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प्रश्न
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.
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उत्तर
- Element A is lithium (Li).
Element B is neon (Ne). - Atomic number of element A is 3.
Atomic number of element B is 10.
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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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−
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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?
How many rows and columns are there in the modern periodic table?
Fill in the following blank with suitable word:
The horizontal rows in a periodic table are called ...............
What is meant by a group, in a periodic table?
where should hydrogen be placed in the modern periodic table? Give reason for your answer.
On which side of the periodic table will you find metals?
Explain why, the noble gases are placed in a separate group.
Consider the following elements:
Na, Ca, Al, K, Mg, Li
Which of these elements belong to the same group of the periodic table?
Which element has the electronic configuration 2, 8, 2?
How does the chemical reactivity of the halogens vary on going in group 17 of the periodic table?
State whether the following statement is true or false:
On going down in a group of the periodic table, the number of valence electrons increases.
Explain why All the elements of a group have similar chemical properties.
Explain why All the elements of a period have different chemical properties.
Explain why, the first period of the periodic table has only two elements whereas second period has eight elements
What is the number of elements is 1st period the modern periodic table?
In what respects do the properties of group 1 elements differ from those of group 17 elements? Explain with examples by taking one element from each group.
Name two elements in each case:
Actinides
Name the type of elements which have two outermost shell incomplete.
Name an alkali metal in period 3 and halogen in period 2.
An element E has following electronic configuration:
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K |
L |
M |
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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.
Answer the following question.
How it can be proved that the basic structure of the Modern Periodic Table is based on the electronic configuration of atoms of different elements?
In the Modern Periodic Table – atoms of all elements are arranged according to their increasing order of – atomic numbers. An atom of nitrogen has seven protons and seven electrons. State what would be its atomic number.
Give the symbol and valency of the following element and radical.
Oxygen [Oxide]
Give the symbol and valency of the following element and radical.
Sulphate
Fill in the blank:
The element lithium in the Modern Periodic Table with valency 1+ belongs to the group ______.
State the number of elements in Period 3 of the Periodic Table.
Which of the following statements about the Modern periodic table is correct?
Write an explanation.
Period
Write a scientific reason.
Lithium and sodium are included in the same group in the periodic table.
Noble gases belong to______ group of the periodic table.
______ and ______ are called inner transition elements.
How does the property vary in periods and in groups?
The arrangement of elements in the Modem Periodic Table is based on their ______
On moving from left to right in a period in the periodic table, the size of the atom ______
Which of the following elements would lose an electron easily?
Group 16 elements are collectively called as ______.
Name two elements that you would expect to show chemical reactions similar to calcium. What is the basis of your choice?
Answer the following in respect of element \[\ce{_16^32S}\].
Give its electronic configuration.
Give reason for the following:
Inert gases do not form ion.
