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प्रश्न
Name or state following with reference to the element of the first three periods of the periodic table.
A metal in period 3 having valency 3.
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उत्तर
Metal in period 3 is A1 [Aluminium]
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संबंधित प्रश्न
The elements Be, Mg and Ca each having two electrons in their outermost shells are in periods 2, 3, and 4 respectively of the modern periodic table. Answer the following questions, giving justification in each case:-
(i) Write the group to which these elements belong.
(ii) Name the least reactive element.
(iii) Name the element having largest atomic radius.
An element 'X' belong to 3rd period and group 13 of the Modern Periodic Table.
(a) Determine the valence electrons and the valency of 'X'.
(b) Molecular formula of the compound formed when 'X' reacts with an element 'Y' (atomic number = 8).
(c) Write the name and formula of the compound formed when 'X' combines with chlorine
How does the number of valence electrons vary on moving from left or right in the second period of the periodic table?
How does Chemical reactivity of elements change on going from left to right in a period of the periodic table?
Give example in support of your answer.
On moving from left to right in a period of the periodic table, the atomic number of elements increases. What happens to the size of atoms of elements on moving from left to right in a period?
(a) increases
(b) decreases
(c) remain the same
(d) first increases then decreases
State the valency of the elements of periods 3 and write the formula of their oxides.
Name the element which has the electronic configuration 2, 8, 3?
On the basis of electronic configuration, how will you identify the first and the last element of a period?
Give the number of the group and the period of elements having three shells with three electrons in valence shell.
Complete the table pertaining to the following elements given in Column I.
| Column I Elements | Atomic Number | Electronic Configuration | Underline the element present in that group |
| 1. Hydrogen | 1 | ______ | Be/Na/Ca |
| 2. Carbon | 6 | ______, ______ | N/P/Si |
| 3. Nitrogen | 7 | _______, ______ | C/P/S |
| 4. Oxygen | 8 | _______, ______ | N/S/Cl |
| 5. Sulphur | 16 | _____, ______, _______ | O/N/F |
| 6. Chlorine | 17 | _____, ______, ______ | I/O/S |
