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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
Two elements ‘P’ and ‘Q’ belong to the same period of the modern periodic table and are in Group 1 and Group 2, respectively. Compare their following characteristics in tabular form:-
(a) The number of electrons in their atoms
(b) The sizes of their atoms
(c) Their metallic character
(d) Their tendencies to lose electrons
(e) The formula of their oxides
(f) The formula of their chlorides
How many groups and periods are there in the modern periodic table?
Define the term : Valency
Which element has the electronic configuration 2, 8, 2?
An element Z has atomic number 16. Answer the following questions on Z:
1) State the period and group to which Z belongs
2) Is Z a metal or a non-metal?
3) State the formula between Z and hydrogen
4) What kind of a compound is this?
Fill in the blank in the following statement:
In going across a period (right to left) in periodic table, the atomic size of the atom ...............
How do atomic structures (electron arrangements) change in a period with increase in atomic numbers from left to right?
How does the tendency to gain electrons change as we go down in group 17 of the periodic table? Why does it change this way?
In which part of a group would you separately expect the elements to have the greatest metallic character
Why does the size of the atoms progressively become smaller when we move from sodium (Na) to chlorine (Cl) in the third period of the periodic table?
In each of the following pair, choose the atom having the bigger size:
Na (At. No. 11) or K (At. No. 19)
What do you understand by periodicity?
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 `
An element barium has atomic number 56. Look up its position in the periodic table and answer the following question.
Is it more or less reactive than calcium?
F, Cl and Br are the elements each having seven valence electrons. Which of these (i) has the largest atomic radius, (ii) is most reactive? Justify your answer stating reason for each.
How do you calculate the possible valency of an element from the electronic configuration of its atoms?
State whether the following statement is true or false
On moving horizontally across a period, number of valence electrons increases from one to eight.
Explain, the statement 'In each period, the atomic radii gradually decrease with increase in atomic number'. Give one example to justify your answer.
The following questions refer to the Periodic Table.
Name the first and last element in period 2.
The following questions refer to the Periodic Table.
What is the common feature of the electronic configurations of the elements in group 7?
Consider the section of the periodic table given below :
| Group numbers |
IA | IIA | IIIA | IVA | VA | VIA | VIIA | O |
| 1 | 2 | 13 | 14 | 15 | 16 | 17 | 18 | |
| Li | D | O | J | Ne | ||||
| A | Mg | E | Si | H | K | |||
| B | C | F | G | L |
With reference to the table, answer the following :
(i) Which is the most electro negative ?
(ii) How many valence electrons are present in G ?
(iii) Write the formula of the compound between B and H ?
(iv) In the compound between F and J, what type of bond will be formed ?
(v) Draw the electron dot structure for the compound formed between C and K.
Give the number of the group and the period of elements having three shells with three electrons in valence shell.
Choose the correct answer from the choice given:
An element A belonging to Period 3 and Group II will have
Use the letters only written in the Periodic Table given below to answer the questions that follow:
(a) State the number of valence electrons in the atom J.(b) Which element shown forms ions with a single negative charge?
(c) Which Metallic element is more reactive than R?
(d) Which element has its electrons arranged in four shells?
Arrange the following as per instruction given in the bracket.
Cl, F, Br, I (increasing electron affinity)
Arrange the following as per instruction given in the bracket.
Cs, Na, Li, K, Rb (decreasing electronegativity)
Arrange the following in order of increasing radii:
Mg2+, Mg, Mg+
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 |
Place the three elements fluorine, beryllium and nitrogen in the order of increasing electronegativity.
The position of elements A, B, C, D and E in the periodic table are shown below:
|
Group 1 |
Group 2 |
Group 17 |
Group 18 |
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D |
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B |
C |
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A |
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E |
State which is metals, non-metals, and noble gas in this table.
The position of elements A, B, C, D and E in the periodic table are shown below:
|
Group 1 |
Group 2 |
Group 17 |
Group 18 |
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D |
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B |
C |
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A |
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E |
State which is most reactive (i) metal (ii) non-metal
The position of elements A, B, C, D and E in the periodic table are shown below:
|
Group 1 |
Group 2 |
Group 17 |
Group 18 |
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D |
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B |
C |
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A |
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E |
Which is larger in size (i) D or E (ii) B or C
Moving left to right in the second period, the number of valence electrons _____.
(a) Fill in the blanks and rewrite the completed statements:
(i) ________ group in the periodic table contains elements that are all gases at room temperature.
(ii) Very fine particles mainly scatter ______ light.
Name the elements in Period 1.
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.
There are three elements E, F, G with atomic numbers 19, 8 and 17 respectively.
Classify the above elements as metals and non-metals.
Match the option A and B with the statements (i) and (ii):
| A. metal | (i) The metal that forms two types of ion. |
| B. iron | (ii) An element with electronic configuration 2, 8, 8, 3. |
