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प्रश्न
Write the electronic configuration of K and Ne.
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उत्तर
| Element | Electronic configuration |
| K | 2,8,8,1 |
| Ne | 2,8 |
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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.
From the following elements :
4Be; 9F; 19K; 20Ca
(i) Select the element having one electron is the outermost shell.
(ii) two elements of the same group.
Write the formula of and mention the nature of the compound formed by the union of 19K and element X(2, 8, 7).
The electrons in the atoms of four elements A, B, C and D are distributed in three shells having 1, 3, 5 and 7 electrons in the outermost shell respectively. State the period in which these elements can be placed in the modern periodic table. Write the electronic configuration of the atoms of A and D and the molecular formula of the compound formed when A and D combine.
Write the number of horizontal rows in the modern periodic table. What are these rows called?
Consider two elements 'A' (Atomic number 17) and 'B' (Atomic number 19) :
(i) Write the positions of these elements in the modern periodic table giving justification.
(ii) Write the formula of the compound formed when 'A' combines with 'B.'
(iii) Draw the electron dot structure of the compound and state the nature of the bond formed between the two elements.
Which element has the electronic configuration 2, 8, 2?
Which element has twice as many electrons in its second shell as in its first shell?
In the following set of element, one element does not belong to the set. Select this element and state why it does not belong:
Calcium, Magnesium, Sodium, Beryllium
How does the number of valence electrons vary on moving from left or right in the second period of the periodic table?
How does the valency of elements change of moving from left to right in the third period of the periodic table?
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 ...............
The atomic radii of three elements X, Y and Z of a period of the periodic table are 186 pm; 104 pm and 143 pm respectively. Giving a reason, arrange these elements in the increasing order of atomic numbers in the period.
Why sodium element of group 1 and chlorine element of group 17 both have valency 1?
Why are noble gases placed in a separate group?
An element has 2 electrons in its N shell.
State the name assigned to this group.
Name the non-metals present in period 2 and metals in period 3.
Atomic number of metal ‚A‛ is 11, while atomic number of metal ‚B‛ is 20. Which of them will be more reactive? Write the chemical reaction of dilute HCl with metal ‚A‛.
Arrange the following in increasing order of property indicated
SiO2, P2O5, SO3, Cl2O7 (acidic nature)
Explain, the statement 'In each period, the atomic radii gradually decrease with increase in atomic number'. Give one example to justify your answer.
'In a group, the atomic radii increase with increasing period number', explain this statement and justify it with reference to group 17.
Name the elements in period 1.
Copy and complete the following sentence choosing the correct word or words from those given below, at the end of the sentence:
The similarities in the properties of elements belonging to a group are because they have the same ______
What is meant by a group in the periodic table?
Arrange the following as per instruction given in the bracket.
Mg, Cl, Na, S, Si (decreasing order of atomic size)
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 |
|
|
|
|
D |
|
|
B |
C |
|
|
A |
|
|
E |
State which is most reactive (i) metal (ii) non-metal
An element A has 2 electrons in its fourth shell. State:
its valency
An element A has 2 electrons in its fourth shell. State:
is it a metal or non-metal
An element A has 2 electrons in its fourth shell. State:
is it an oxidising or reducing agent
Answer the following question:
State the four blocks of the modern periodic table based on the electronic configuration of elements.
The electronic configuration of an element is 2, 8, 4. State it:
name and write its one physical property.
What is the common feature of the electronic configuration of the elements at the end of Period 2 and Period 3?
Name or state following with reference to the element of the first three periods of the periodic table.
The non-metallic element present in period 3 other than sulphur and chlorine.
Select the correct answer from the options given below.
It is a metal in period 2 having electronic configuration 2, 1?
Fill in the blanks from the words A to F given below’.
A: Decreases
B: Increases
C: Remains same
D: Increases by one
E: Electropositive
F: Electronegative
Across a period from left to right in the Modern Periodic Table.
No. of electron shells _________; No. of valence electrons __________: Electronegativity increases Character of elements changes from electropositive to ________.
State the following:
The group to which the element with an electronic configuration of 2, 8, 2 belongs.
State the following:
The group which contains highly electropositive metals including sodium.
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. |
