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प्रश्न
Why do we classify elements?
उत्तर
Elements are classified into certain groups in such a manner that elements belonging to the same group exhibit similar properties. This eases the study of elements, as we can reduce the study to a few groups of elements rather than studying the properties of all the 115 elements known at present, which is very difficult. This is the reason for classification of elements.
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संबंधित प्रश्न
An atom has the electron structure of 2, 7.
(a) What is the atomic number of this atom?
(b) To which of the following would it be chemically similar?
7N, 15P, 17Cl, 18Ar
(c) Why would you expect it to be similar?
An element X combines with oxygen to form an oxide XO. This oxide is electrically conducting.
(a) How many electrons would be there in the outermost shell of the element X?
(b) To which group of the periodic tables does the element X belong?
(c) Write the formula of the compound formed when X reacts with chlorine.
Atoms of eight elements A, B, C, D, E, F, G and H have the same number of electron shells but different number of electrons in their outermost shells. It was found that elements A and G combine to form an ionic compound. This ionic compound is added in a small amount to almost all vegetables and dishes during cooking. Oxides of elements A and B are basis in nature while those of elements E and F acidic. The oxide of element D is, however, almost neutral. Based on the above information, answer the following questions:
(a) To which group or period of the periodic table do these elements belong?
(b) What would be the nature of compound formed by a combination of elements B and F?
(c) Which two of these elements could definitely be metals?
(d) Which one of the eight elements is most likely to be found in gaseous state at room temperature?
(e) If the number of electrons in the outermost shell of elements C and G be 3 and 7 respectively, write formula of the compound formed by the combination of C and G.
Alkaline earth metals have valency 2. This means that their position in the modern periodic table is in ______.
What was the basis of the earliest attempts made for classification and grouping of elements?
Classify the following elements into Metals and Nonmetals.
S, Mg, Al, P, N, Na.
State whether true or false. If false, correct the statement.
Metals can gain electrons.
What property forms the basis of identification?
An element X combines with oxygen to form an oxide XO. This oxide is electrically conducting. Write the formula of the compound formed when X reacts with chlorine.
Which type of elements are poor conductors of heat and electricity?
