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प्रश्न
Answer the following question:
State the four blocks of the modern periodic table based on the electronic configuration of elements.
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उत्तर
Elements in the modern periodic table are classified on the basis of their electronic configuration. They are divided into four blocks: s – block, p – block, d – block, and f – block.
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संबंधित प्रश्न
Given below are some elements of the modern periodic table. Atomic number of the element is given in parentheses.
A(4), B(9), C(14), D(19), E(20)
(a) Select the element that has one electron in the outermost shell. Also, write the electronic configuration of this element.
(b) Which two elements amongst these belong to the same group? Give reasons for your answer.
(c) Which two elements amongst these belong to the same period? Which one of the two has bigger atomic radius?
An element 'X' has mass number 35 and number of neutrons 18. Write atomic number and electronic configuration of 'X'. Also write group number, period number and valency of 'X'.
Na, Mg and Al are the elements of the same period of Modern Periodic Table having, one, two and three valence electrons respectively. Which of these elements (i) has the largest atomic radius, (ii) is least reactive? Justify your answer stating reason for each case.
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.
Write any one difference in the electronic configurations of group-1 and group-2 elements ?
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?
How does the number of valence electrons vary on moving from left or right in the first period of the periodic table?
Rewrite the following statement after correction, if necessary:
The metallic character of elements in a period increases gradually on moving from left to right.
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.
How does the electropositive character of elements change on going down in a group of the periodic table?
In terms of electronic configurations, explain the variation in the size of the atoms of the elements belonging to the same period and same group ?
Why sodium element of group 1 and chlorine element of group 17 both have valency 1?
Correct the statements.
Elements in the same periods have equal valency.
What do you understand by orbits?
What is its atomic number?
An element X belong to 4th period and 17th group, state.
name of the element.
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 `
Complete the following sentences
The similarities in the properties of a group of elements are because they have the same …………………
Chorine in the periodic table is surrounded by the elements with atomic number 9, 16, 18 and 35.
Which is more electronegative than chlorine?
State the number of elements in periods 1, Periods 2, and Period 3 of the periodic table. Name them.
What is the common feature of the electronic configuration of the elements at the end of period 2, and period 3?
Write two reasons responsible for late discovery of noble gases ?
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.
Fill in the blank
Oxidising property ________from fluroine to iodine because the power to accpet electron decreases.
'In a group, the atomic radii increase with increasing period number', explain this statement and justify it with reference to group 17.
State the number of elements in period 1, period 2 and period 3 of the periodic table.
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.
Li, K, Na, H ( decreasing order of their potential ionisation )
An element A has 2 electrons in its fourth shell. State:
is it an oxidising or reducing agent
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?
What is the common feature of the electronic configuration of the elements at the end of Period 2 and Period 3?
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 _______.
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.
Electron Affinity is maximum in ______.
