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प्रश्न
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.
उत्तर
(a) The elements belong to the third period of the periodic table, and have the same number of electron shells but different number of electrons in their outermost shells. The number of valence electrons in these elements increases from 1 to 8, on moving from left to right in this period.
(b) When metal B combines with a non-metal F, an ionic compound is formed due to the transfer of electrons from the metal to the non-metal. This is because in the third period, elements A, B and C are metals, D is a metalliod, and E, F, G and H are non-metals.
(c) A and B are definitely metals because in the 3rd period, at the extreme left, only metals are placed in the periodic table .
(d) The element H is most likely to be found in a gaseous state at room temperature. This is because the last group elements in the periodic table are all in a gaseous state at room tempearture.
(e) If the number of valence electrons of element C is 3 and those of element G is 7, then 1 atom of element C will combine with 3 atoms of element G to form a compound with the formula CG3.
संबंधित प्रश्न
An element P (atomic number 20) reacts with an element Q (atomic number 17) to form a compound. Answer the following questions giving reason:
Write the position of P and Q in the Modern Periodic Table and the molecular formula of the compound formed when P reacts with Q.
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.
A metal X is in the first group 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?
Why was this basis of classification discarded for future classification of elements?
Elements belonging to the same group have the same valency.
Write the name.
The atom having smallest atomic radius from group 1.
Among the given species A–, A+, and A, the smallest one in size is ______.
An element with the atomic number 40 is placed in the period.
Complete the following triads by inserting the missing elements.
Li, ______, K
