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प्रश्न
Choose the correct option and rewrite the statement.
The number of electrons in the outermost shell of alkali metals is _______.
विकल्प
1
2
3
7
उत्तर
The number of electrons in the outermost shell of alkali metals is 1.
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संबंधित प्रश्न
Rewrite the following statement after correction, if necessary:
Periods are the horizontal rows of elements.
The element which can from an acidic oxide should be the one whose atomic number is:
(a) 6
(b) 16
(c) 12
(d) 19
An element Y is in second period and group 16 of the periodic table:
(i) Is it a metal or non-metal?
(ii) What is the number of valence electrons in its atom?
(iii) What is its valency?
(iv) What is the name of the element?
(v) What will be the formula of the compound formed by Y with sodium?
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?
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):
-
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?
The elements Li, Na and K, each having one valence electron, are in period 2, 3 and 4 respectively of modern periodic table.
(i) In which group of the periodic table should they be ?
(ii) Which one of them is least reactive ?
(iii) Which one of them has the largest atomic radius ? Give reason in justify your answer in each case.
The molecular formula of the chloride of element X is XCl. This compound is a solid having a high melting point. Which of the following elements be present in the same group as X.
In which block of the modern periodic table are the nonmetals found?
(a) How is possible valency of an element determined from the electronic configuration of its atom ?
(b) Determine the valency of an element X whose atomic number is 15.
Give a reason why elements need to be properly classified.
Example for liquid metal is ______.
The number of periods and groups in the periodic table are ______
Among the given species A–, A+, and A, the smallest one in size is ______.
Identify the bond between H and F in the HF molecules.
What is the atomic number of elements of period 3 and group 17 of the Periodic Table?
Which of the following hydroxides is most basic?
Which one of the following does not increase while moving down the group of the periodic table?
Element ‘A’ has electronic configuration 2, 7; ‘B’ has electronic configuration 2, 8, 5 and ‘C’ has electronic configuration 2, 8, 7. Which two elements will exhibit similar chemical properties?
Complete the following triads by inserting the missing elements.
Li, ______, K
