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प्रश्न
Fill in the blank and rewrite the completed statement:
________ group in the periodic table contains elements that are all gases at room temperature.
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उत्तर
The 18th group in the periodic table contains elements that are all gases at room temperature.
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संबंधित प्रश्न
Fill in the blank:
The formulae of chloride of metal M is MCl2. The metal M belongs to ……………. group.
Study the following table in which positions of six elements A, B, C, D, E and F are shown as they are in the modern periodic table:
|
Group→
Period↓ |
1
|
2
|
3-12
|
13
|
14
|
15
|
16
|
17
|
18
|
| 2 | A | B | C | ||||||
| 3 | D | E | F |
On the basis of the above table, answer the following questions:-
(i) Name the element which forms only covalent compounds.
(ii) Name the element which is a metal with valency three.
(iii) Name the element which is a non-metal with valency three.
(iv) Out of D and E, which is bigger in size and why?
(v) Write the common name for the family to which the elements C and F belong.
The position of eight elements in the Modern Periodic Table is given below where atomic numbers of elements are given in the parenthesis.
| Period No. | ||
| 2 | Li(3) | Be(4) |
| 3 | Na(11) | Mg(12) |
| 4 | K(19) | Ca(20) |
| 5 | Rb(37) | Sr(38) |
(i) Write the electronic configuration of Ca.
(ii) Predict the number of valence electrons in Rb.
(iii) What is the number of shells in Sr?
(iv) Predict whether K is a metal or a non – metal.
(v) Which one of these elements has the largest atom in size?
(vi) Arrange Be, Ca, Mg and Rb in the increasing order of the size of their respective atoms.
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.
An element 'M' with electronic configuration (2, 8, 2) combines separately with (NO3)–, (SO4)2– and (PO4)3– radicals. Write the formula of the three compounds so formed. To which group and period of the Modern Periodic Table does the element 'M' belong? Will 'M' form covalent or ionic compounds? Give reason to justify your answer.
Differentiate between Normal elements and Transition elements.
How do electronic configurations of elements change in second period of periodic table with increase in atomic numbers?
How does the size of atoms (atomic size) generally vary in going from left to right in a period of the periodic table? Why does it vary this way?
What happens to the metallic character of the elements as we move from left to right in a period of the periodic table?
Why do elements in the same group show similar properties but the elements in different groups show different properties?
Five elements A, B, C, D and E have atomic numbers of 2, 3, 7, 10 and 18 respectively. The elements which belong to the same period of the periodic table are:
(a) A, B, C
(b) B, C, D
(c) A, D, E
(d) B, D, E
Where would you locate the element with electronic configuration 2, 8 in the modern periodic table?
The atomic numbers of the elements Na, Mg, K and Ca are 11, 12, 19 and 20 respectively. The element having the largest atomic radius is:
(a) Mg
(b) Na
(c) K
(d) Ca
Which of the following set of elements is written correctly in the order of their increasing metallic character?
(a) Mg, Al, Si
(b) C, O, N
(c) Na, Li, K
(d) Be, Mg, Ca
What do you understand by periodicity?
Why are noble gases placed in a separate group?
An element A has atomic number 14. To which period does this element belong and how many elements are there in this period.
Why fluorine has higher E.N. than chorine?
How does the number of:
valence electrons and
How does the number of:
valency vary on moving from left to right in the second period of the periodic table?
An element X belong to 3rd periods and group II of the periodic table state:
the number of valence electrons,
An element X belong to 3rd periods and group II of the periodic table state:
the valency,
An element 'M' has atomic number 12.
(a) Write its electronic configuration.
(b) State the group to which 'M' belongs.
(c) Is 'M' a metal or a non-metal.
(d) Write the formula of its chloride.
Select the correct answer
Number of shells in potassium are
Select the correct answer
Identify the metalloid
What is meant by a group in the periodic table?
Parts (i) to (v) refer to changes in the properties of elements on moving from left to right across a period of the periodic table. For each property, choose the letter corresponding to the correct answer from the choices (a), (b), (c) and (d).
(i) The non metallic character of the elements:
(a) Decreases
(b) Increases
(c) Remains the same
(d) Depends on the period
(ii) The electro negativity
(a) Depends on the number of valence electrons
(b) Remains the same
(c) Decreases
(d) Increases
(iii) The ionization potential
(a) Goes up and down
(b) Decreases
(c) Increases
(d) Remains the same
(iv) The atomic size
(a) Decreases
(b) Increases
(c) Remains the same
(d) Sometimes increases and sometimes decreases
(v) The electron affinity of the elements in groups 1 to 7:
(a) Goes up and down
(b) Decreases and then increases
(c) Increases
(d) decreases
Choose the correct answer from the choice given:
An element A belonging to Period 3 and Group II will have
Choose the most appropriate answer from the following list of oxides which fit the description.
An amphoteric oxide.
Arrange the following as per instruction given in the bracket.
Mg, Cl, Na, S, Si (decreasing order of atomic size)
Name and state the following with reference to the elements of the first three periods of the periodic table.
Metalloid in Period 3.
Moving down in the second group, number of valence electrons ______.
Based on the group valency of element write the molecular formula of the following compound giving justification:
Compound formed when an element A of group 2 combines with an element B of group seventeen.
The position of certain elements in the Modern Periodic Table is shown below:
| Group → Period ↓ |
1 | 2 | 3 to 12 | 13 | 14 | 15 | 16 | 17 | 18 |
| 1 | G | H | |||||||
| 2 | A | I | B | C | |||||
| 3 | D | E | F |
Using the above table answer the following questions giving reasons in each case:
- Which element will form only covalent compounds?
- Which element is a non-metal with valency 2?
- Which element is a metal with valency 2?
- Out of H, C, and F which has the largest atomic size?
- To which family does H, C, and F belong?
Select the correct answer from the options given below.
It is a period having elements from atomic no. 11 to 18.
Select the correct answer from the options given below.
Is the group number of the element whose atomic number is 4.
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 |
