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प्रश्न
What is the need for classification of elements?
उत्तर
It is impossible for a chemist to study all the elements and their compounds. Hence, classification is a must.
Following are the reasons for the classification of elements:
- To study elements better
- To correlate the properties of the elements with some fundamental properties which are characteristic of all the elements
- To reveal relationships between elements
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संबंधित प्रश्न
State whether the following statement is true of false:
The elements in a group have consecutive atomic numbers.
An element X is in group 2 of the periodic table what will be the formula of its oxide?
The following diagram shows a part of the periodic table containing first three periods in which five elements have been represented by the letters a, b, c, d and e (which are not their chemical symbols):
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1 18 a 2 13 14 15 16 17 b c d e
(i) Select the letter which represents an alkali metal.
(ii) Select the letter which represents a nobles gas.
(iii) Select the letter which represents a halogen.
(iv) What type of bond is formed between a and e?
(v) What type of bond is formed between d and e?
A non-metal X which is the largest constituent of air combines with hydrogen when heated in the presence of iron as catalyst to form a gas Y. When gas Y is treated with sulphuric acid, it forms a compound Z which is used as a chemical fertiliser.
(a) What are X, Y and Z?
(b) To which group of periodic table does X belong?
(c) Name the periodic table in which X is placed.
(d) Which element is placed just before X in the period?
(e) Which element is placed just after X in the period?
Identify the bond between H and F in the HF molecules.
What property forms the basis of identification?
The elements of group 16 are called ______
Which of the following property will be common in group 1 elements?
What type of oxide would Eka– aluminium form?
Complete the following triads by inserting the missing elements.
Ca, ______, Ba
