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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
How do the atomic size and metallic character of elements vary as we move :-
(a) down a group and
(b) from left to right in a period
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.
List any two properties of the elements belonging to the first group of the modern periodic table.
What is meant by 'group' in the modern periodic table? How do the following change on moving from top to bottom in a group?
(i) Number of valence electrons
(ii) Number of occupied shells
(iii) Size of atoms
(iv) Metallic character of element
(v) Effective nuclear charge experienced by valence electrons
Based on the group valency of elements state the formula lot the following giving justification for each :-
(i) Oxides of 1st group elements,
(ii) Halides of the elements of group 13, and
(iii) Compounds formed when an element of group 2 combines with, an element of group 16.
Rewrite the following statement after correction, if necessary:
The metallic character of elements in a period increases gradually on moving from left to right.
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?
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
The atomic numbers of three elements A, B and C are given below:
| Element | Atomic number |
| A | 5 |
| B | 7 |
| C | 10 |
(i) Which element belongs to group 18?
(ii) Which element belongs to group 15?
(iii) Which element belongs to group 13?
(iv) To which period/periods do these elements belong?
Name the element which has the electronic configuration 2, 8, 3?
Chorine in the periodic table is surrounded by the elements with atomic number 9, 16, 18 and 35.
Which of these have physical and chemical properties resembling chlorine.
State the number of elements in periods 1, Periods 2, and Period 3 of the periodic table. Name them.
name the elements in period 1.
How do you calculate the possible valency of an element from the electronic configuration of its atoms?
How many groups and periods are there in the modern periodic table?
'In a group, the atomic radii increase with increasing period number', explain this statement and justify it with reference to group 17.
What is the common feature of electronic configurations of the elements at the end of period 2 and period 3?
The following questions refer to the Periodic Table.
Name the first and last element in period 2.
Choose the most appropriate answer from the following list of oxides which fit the description.
A basic oxide.
Arrange the following as per instruction given in the bracket.
Mg, Cl, Na, S, Si (decreasing order of atomic size)
Arrange the following as per instruction given in the bracket.
K, Pb, Ca, Zn (increasing reactivity)
The elements of one short period of the periodic table are given below in order from left to right:
| Li | Be | B | C | O | F | Ne |
To which period do these elements belong?
An element belongs to the third period and Group IIIA (13) of the periodic table. State: the valency,
Name and state the following with reference to the elements of the first three periods of the periodic table.
Metalloid in Period 3.
State the nature of compounds formed when group 17 elements combine with (i) metals (ii) non-metals.
Moving left to right in the second period, the number of valence electrons _____.
The electronic configuration of an element is 2, 8, 4. State it:
group and period in the Modern Periodic Table.
Based on the group valency of element write the molecular formula of the following compound giving justification:
Oxide of first group elements.
Name the elements in Period 1.
Supply the missing word from those in bracket:
If an element has one electron in its outermost energy level [shell] then it is likely to be _______.
The similarities in the properties of a group of elements are because they have the same ______.
State the property trends in general of elements on moving from left to right in a period of the periodic table.
Name or state following with reference to the element of the first three periods of the periodic table.
A non-metal in period 2 having electronic configuration 2, 6.
Name or state following with reference to the element of the first three periods of the periodic table.
The formula of the hydroxide of the element having electronic configuration 2, 8, 2.
Select the correct answer from the options given below.
Is the group number of the element whose atomic number is 4.
Which of the following would weigh the least?
(Atomic masses C = 12, 0 = 16, Na = 23)
