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प्रश्न
The similarities in the properties of a group of elements are because they have the same ______.
विकल्प
electronic configuration
number of outer electrons
atomic numbers
उत्तर
The similarities in the properties of a group of elements are because they have the same number of outer electrons.
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संबंधित प्रश्न
Calcium is an element with atomic number 20. Stating reason, answer each of the following questions:-
(i) Is calcium a metal or a non-metal?
(ii) Will its atomic radius be larger or smaller than that of potassium with atomic number 19?
(iii) Write the formula of its oxide.
Na, Mg and Al are the elements of the same period of Modern Periodic Table having, one, two and three valence electrons respectively. Which of these elements (i) has the largest atomic radius, (ii) is least reactive? Justify your answer stating reason for each case.
Write the number of periods the Modern Periodic Table has. State the changes in valency and metallic character of elements as we move from left to right in a period. Also state the changes, if any, in the valency and atomic size of elements as we move down a group.
Consider two elements 'X' (Atomic number 17) and 'Y' (Atomic number 20)
(i) Write the positions of these elements in the modern periodic table giving justification.
(ii) Write the formula of the compound formed by the combination of 'X' and 'Y'.
(iii) Draw the electron-dot structure of the compound formed and state the nature of the bond formed between the two elements ?
Fill in the blank in the following statement:
On going down in a group in the periodic table, the metallic character of elements ...............
For each of the following triads, name the element with the characteristics specified below:
| Elements | Least atomic radius | Chemically least reactive |
| (i) F, Cl, Br (ii) Li, Na, K |
.................... .................... |
.................... .................... |
In terms of electronic configurations, explain the variation in the size of the atoms of the elements belonging to the same period and same group ?
Which of the following element does not lose an electron easily?
(a) Na
(b) F
(c) Mg
(d) Al
Where would you locate the element with electronic configuration 2, 8 in the modern periodic table?
State the valency of the elements of periods 3 and write the formula of their oxides.
An element X belong to 4th period and 17th group, state.
Write the formula of the compound formed when it reacts with `(27)/(13) y `
Complete the following sentences
The similarities in the properties of a group of elements are because they have the same …………………
Fill in the blank
There are ______ groups and ______ periods in the modern form of periodic table.
Explain
Size of atom changes when it loses or gain electron
Select the correct answer
Identify the metalloid
Atomic number of an element is 16. State
- the period to which it belongs
- the number of valence electrons
- whether it is a metal or non-metal
Choose the word or phrase from the bracket which correctly complete each of the following statement:
Metals are good ................. (oxidising agents/reducing agents) because they are electron ............. (acceptors/donors).
Moving left to right in the second period, the number of valence electrons _____.
Name the elements in the correct order of their increasing atomic numbers present in the first, second, and third short periods of the periodic table.
State which of the elements are –
- metallic
- non-metallic
- noble gases
in each of the periods 2 and 3.
Name or state following with reference to the element of the first three periods of the periodic table.
The valency of elements in group 1 [I–A].
