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प्रश्न
Write the electronic configuration of K and Ne.
उत्तर
| Element | Electronic configuration |
| K | 2,8,8,1 |
| Ne | 2,8 |
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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
Taking the example of an element of atomic number 16, explain how the electronic configuration of the atom of an element relates to its position in the modern periodic table and how valency of an element is calculated on the basis of its atomic number.
The elements 4Be, 12Mg and 20Ca, each having two valence electrons in their valence shells, are in periods 2, 3 and 4 respectively of the modern periodic table. Answer the following questions associated with these elements, giving reason in each case:
(a) In which group should they be?
(b) Which one of them is least reactive?
(c) Which one of them has the largest atomic size?
How many groups and periods are there in the modern periodic table?
What happens to the metallic character of the elements as we go down in a group of the periodic table?
How does the number of valence electrons vary on moving from left or right in the second period of the periodic table?
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.
What happens to the metallic character of the elements as we move from left to right in a period of the periodic table?
Explain why, the properties of elements are repeated after 2, 8, 18 and 32 elements in the periodic table.
The atomic number of an element is 20. In modern periodic table, this element is placed:
(a) 2nd period
(b) 4th period
(c) 3rd period
(d) 1st period
Which of the following element would lose an electron easily?
(a) Mg
(b) Na
(c) K
(d) Ca
Which of the following is the valence shell for the elements of second period of the modern periodic table?
(a) M shell
(b) K shell
(c) L shell
(d) N shell
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
Periodicity is observed due to the similar ______.
What is its atomic number?
An element X belong to 4th period and 17th group, state.
no of valence electrons in it
An element X belong to 3rd periods and group II of the periodic table state:
the number of valence electrons,
State the number of elements in periods 1, Periods 2, and Period 3 of the periodic table. Name them.
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.
Calculate the valency of element X whose atomic number is 9.
On the basis of electronic configuration, how will you identify the first and the last element of a period?
What is modern periodic law?
What is meant by periodicity of elements?
Select the correct answer
Identify the metalloid
What is the common feature of electronic configurations of the elements at the end of period 2 and period 3?
Choose the most appropriate answer from the following list of oxides which fit the description.
An amphoteric oxide.
With reference to the variation of properties in the Periodic table, which of the following is generally true?
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 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 |
|
|
|
|
D |
|
|
B |
C |
|
|
A |
|
|
E |
Which type of ion will be formed by elements A, B, and C.
Element P has atomic number 19. To which group and period, does P belong? Is it a metal or a non-metal? Why?
Name and state the following with reference to the elements of the first three periods of the periodic table.
Valency of elements in Group 14 and 15.
An element A has 2 electrons in its fourth shell. State:
its valency
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 _______.
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)
