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प्रश्न
Differentiate between Normal elements and Transition elements.
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.
The position of eight elements in the Modern Periodic Table is given below where atomic numbers of elements are given in the parenthesis.
| Period No. | ||
| 2 | Li(3) | Be(4) |
| 3 | Na(11) | Mg(12) |
| 4 | K(19) | Ca(20) |
| 5 | Rb(37) | Sr(38) |
(i) Write the electronic configuration of Ca.
(ii) Predict the number of valence electrons in Rb.
(iii) What is the number of shells in Sr?
(iv) Predict whether K is a metal or a non – metal.
(v) Which one of these elements has the largest atom in size?
(vi) Arrange Be, Ca, Mg and Rb in the increasing order of the size of their respective atoms.
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 atomic numbers of two elements 'X' and 'Y' having electronic configuration 2, 8, 2 and 2, 8, 6 respectively.
Write the number of horizontal rows in the modern periodic table. What are these rows called?
Which element has the electronic configuration 2, 8, 2?
Calculate the number of gram atoms in 4.6 grams of sodium (Na = 23)
Match the atomic number 2, 4, 8, 15 and 19 with each of the following
1) A solid non metal belonging to the third period.
2) A metal of valency 1.
3) A gaseous element with valency 2.
4) An element belonging to Group 2
5) A rare gas.
An element with the atomic number 19 will most likely combine chemically with the element whose atomic number is ______.
Choose the most appropriate answer of the following:
Which of the following would weigh the least?
(A) 2-gram atoms of Nitrogen.
(B) 1mole of Silver
(C) 22.4 liters of oxygen gas at 1 atmospheric pressure and 273K
(D) 6.02 x 1023 atoms of carbon.
[Atomic masses: Ag=108, N=14, O=16, C=12]
How does the number of valence electrons vary on moving from left or right in the first period of the periodic table?
Fill in the blank in the following statement:
On going down in a group in the periodic table, the metallic character of elements ...............
In which part of a group would you separately expect the elements to have the greatest metallic character
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
The atomic numbers of the elements Na, Mg, K and Ca are 11, 12, 19 and 20 respectively. The element having the largest atomic radius is:
(a) Mg
(b) Na
(c) K
(d) Ca
In each of the following pair, choose the atom having the bigger size:
Na (At. No. 11) or K (At. No. 19)
The atomic numbers of three elements A, B and C are given below:
| Element | Atomic number |
| A | 5 |
| B | 7 |
| C | 10 |
(i) Which element belongs to group 18?
(ii) Which element belongs to group 15?
(iii) Which element belongs to group 13?
(iv) To which period/periods do these elements belong?
An element X belong to 4th period and 17th group, state.
name the family to which it belong.
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 …………………
How can the valency of an element be determined if its electronic configuration is known?
How do you calculate the possible valency of an element from the electronic configuration of its atoms?
On the basis of electronic configuration, how will you identify the first and the last element of a period?
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‛.
What is modern periodic law?
Arrange the following in increasing order of property indicated
SiO2, P2O5, SO3, Cl2O7 (acidic nature)
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
The following questions refer to the Periodic Table.
Name the first and last element in period 2.
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.
Choose the most appropriate answer from the following list of oxides which fit the description.
An oxide which dissolves in water forming an acid.
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.
Li, K, Na, H ( decreasing order of their potential ionisation )
Arrange the following in order of increasing radii:
Mg2+, Mg, Mg+
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 is larger in size (i) D or E (ii) B or C
Based on the group valency of element write the molecular formula of the following compound giving justification:
Compound formed when an element A of group 2 combines with an element B of group seventeen.
The similarities in the properties of a group of elements are because they have the same ______.
Name or state following with reference to the element of the first three periods of the periodic table.
The valency of elements in group 1 [I–A].
Name or state following with reference to the element of the first three periods of the periodic table.
A non-metal in period 2 which is tetravalent.
Which of the following would weigh the least?
(Atomic masses C = 12, 0 = 16, Na = 23)
