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प्रश्न
Differentiate between Normal elements and Transition elements.
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उत्तर
| Normal Elements | Transition Elements |
| Elements belonging to groups 1 and 2, and 13 to 17 are called normal elements. | Elements belonging to groups 3 to 12 are called transition elements. |
| In these elements, all the inner shells are completely filled except the outermost shells. |
In these elements, the outermost shell and next to the outermost shell (penultimate shell) are incomplete. |
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संबंधित प्रश्न
Study the following table in which positions of six elements A, B, C, D, E and F are shown as they are in the modern periodic table:
|
Group→
Period↓ |
1
|
2
|
3-12
|
13
|
14
|
15
|
16
|
17
|
18
|
| 2 | A | B | C | ||||||
| 3 | D | E | F |
On the basis of the above table, answer the following questions:-
(i) Name the element which forms only covalent compounds.
(ii) Name the element which is a metal with valency three.
(iii) Name the element which is a non-metal with valency three.
(iv) Out of D and E, which is bigger in size and why?
(v) Write the common name for the family to which the elements C and F belong.
How many groups and periods are there in the modern periodic table?
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.
Classify the following elements into metals, non-metals and metalliods
As, C, Hg, Mg, S, Si
Calculate the number of gram atoms in 4.6 grams of sodium (Na = 23)
What happens to the metallic character of the elements as we go down in a group of the periodic table?
Name the element which is in first group and third period.
Fill in the blank in the following statement:
On moving form right to left in the second period, the number of valency electrons ...............
Fill in the blank in the following statement:
On going down in a group in the periodic table, the metallic character of elements ...............
An element X belongs to group 2 and another element Y belongs to group 15 of the periodic table:
(a) What is the number of valence electron in X?
(b) What is the valency of X?
(c) What is the number of valence electrons in Y?
(d) What is the valency of Y?
Explain how you have arrived at your answers.
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?
State one reason for keeping fluorine and chlorine in the same of the periodic table.
The element which has the maximum number of valence electrons is:
(a) Na
(b) P
(c) Si
(d) A
An element has 2 electrons in its N shell.
State the name assigned to this group.
State the trends in physical properties on moving down the group. Give an example to illustrate.
How does the number of:
valency vary on moving from left to right in the second period of the periodic table?
Fill in the blank:
on moving from right to left in the second period, the number of valence electrons……….
An element X belong to 3rd periods and group II of the periodic table state:
the number of valence electrons,
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.
Four elements P, Q, R and S belong to the third period of the Modern Periodic Table and have respectively 1, 3, 5 and 7 electrons in their outermost shells. Write the electronic configurations of Q and R and determine their valences. Write the molecular formula of the compound formed when P and S combine.
What will be the valency of an element of atomic number 9 (nine)?
Calculate the valency of element X whose atomic number is 9.
What is modern periodic law?
Fill in the blank
Most electropositive elements belong to ______ group.
State the number of elements in period 1, period 2 and period 3 of the periodic table.
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 ______
Parts (i) to (v) refer to changes in the properties of elements on moving from left to right across a period of the periodic table. For each property, choose the letter corresponding to the correct answer from the choices (a), (b), (c) and (d).
(i) The non metallic character of the elements:
(a) Decreases
(b) Increases
(c) Remains the same
(d) Depends on the period
(ii) The electro negativity
(a) Depends on the number of valence electrons
(b) Remains the same
(c) Decreases
(d) Increases
(iii) The ionization potential
(a) Goes up and down
(b) Decreases
(c) Increases
(d) Remains the same
(iv) The atomic size
(a) Decreases
(b) Increases
(c) Remains the same
(d) Sometimes increases and sometimes decreases
(v) The electron affinity of the elements in groups 1 to 7:
(a) Goes up and down
(b) Decreases and then increases
(c) Increases
(d) decreases
Arrange the following as per instruction given in the bracket
Na, K, Cl, S, Si (increasing ionisation potential)
Arrange the following in order of increasing radii:
N, O, P
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
Element P has atomic number 19. To which group and period, does P belong? Is it a metal or a non-metal? Why?
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.
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?
Name or state following with reference to the elements of the first three periods of the periodic table.
The number of electron shells in elements of period 1, period 2, and period 3.
