Advertisements
Advertisements
प्रश्न
State the modern periodic law.
Advertisements
उत्तर
Modern periodic law states that "The physical and chemical properties of all elements are a periodic function of their atomic numbers".
APPEARS IN
संबंधित प्रश्न
In the Modern Periodic Table, which are the metals among the first ten elements?
The position of three elements A, B and C in the Periodic Table are shown below –
|
Group 16
|
Group 17
|
|
−
|
−
|
|
−
|
A
|
|
−
|
−
|
|
B
|
C
|
(a) State whether A is a metal or non-metal.
(b) State whether C is more reactive or less reactive than A.
(c) Will C be larger or smaller in size than B?
(d) Which type of ion, cation or anion, will be formed by element A?
Nitrogen (atomic number 7) and phosphorus (atomic number 15) belong to group 15 of the Periodic Table. Write the electronic configuration of these two elements. Which of these will be more electronegative? Why?
Why do all the elements of the same group have similar properties?
How does the tendency of elements to gain electrons change as we move from left to right in a period? State the reason of this change.
What is meant by a period, in a periodic table?
Give two example of group 18 elements.
How were the positions of cobalt and nickel resolved in the modern periodic table?
Explain why, the noble gases are placed in a separate group.
Would you place the two isotopes of chlorine, CI-35 and CI-37 in different slots because of their different atomic masses or in the same slot because their chemical properties are the same? Justify your answer.
Is it possible to have an element having atomic number 1.5 placed between hydrogen and helium?
What is the number of valence electrons in the atoms of first elements in a period?
What happens to the number of valence electrons in the atoms of elements as we go down in a group of the periodic table?
(b) What is the number of elements is 3rd period, the modern periodic table?
In what respects do the properties of group 1 elements differ from those of group 17 elements? Explain with examples by taking one element from each group.
What are the advantages of the periodic table?
What are the periods in a periodic table? Give two characteristics of each.
Which of the following are the correct characteristics of isotopes of an element?
(i) same atomic mass
(ii) same atomic number
(iii) same physical properties
(iv) same chemical properties
(a) (i), (ii) and (iv)
(b) (ii), (iii) and (iv)
(c) (ii) and (iii)
(d) (ii) and (iv)
The following diagram shows a part of the periodic table in which the elements are arranged according to their atomic numbers. (The letters given here not the chemical symbols of the elements):
| a 3 |
b 4 |
c 5 |
d 6 |
e 7 |
f 8 |
g 9 |
h 10 |
|
| i 11 |
j 12 |
k 13 |
l 14 |
m 15 |
n 16 |
o 17 |
p 18 |
(i) Which element has a bigger atom, a or f?
(ii) Which element has a higher valency, k or o?
(iii) Which element is more metallic i or k?
(iv) Which element is more non-metallic, d or g?
(v) Select a latter which represents a metal of valency 2.
(vi) Select a letter which represents a non-metal of valency 2.
An element X belongs to 3rd period and group 2 of the periodic table. State:
(a) number of valence electrons
(b) valency
(c) metal or non-metal
(d) name of the element
Define:
Periodic table
What are horizontal rows and vertical columns in a periodic table known as?
Arrange the elements of second and third periods in increasing order of their atomic size.
Third Period.
How does the electronic configuration of an atom relate to its position in the modern periodic table?
Fill in the blank:
The horizontal rows in the periodic table are called _____________.
Name the noble gas with 3 shells.
How many periods and groups are there in the modern periodic table?
An element A has 2 electrons in its fourth shell. State its electronic configuration.
Answer the following question.
How it can be proved that the basic structure of the Modern Periodic Table is based on the electronic configuration of atoms of different elements?
Give the symbol and valency of the following element and radical.
Sulphate
State what is meant by the term chemical formula.
Give the chemical formula of sodium nitrate
Give the chemical formula of carbonic acid
The groups 1 and 2 constitute the _______ block.
Group 1 and 2 : s block : : group 13 and 18 : _______
The modern periodic table has 1 to 7 periods.
In the modern periodic table, the positions of 1 to 20 elements are shown here. Identify the elements A and B. Write their atomic number.
Distinguish between:
s-block - p-block
State any five features of modern periodic table.
The scientist who propounded the modern periodic law is ______.
The arrangement of elements in the Modem Periodic Table is based on their ______
Which of these belong to the same period?
| Element | A | B | C |
| Atomic number | 2 | 10 | 5 |
An element has the atomic number 12.
- Write the electric configuration.
- To which group and period does it belong.
A part of modern periodic table is given below. On its basis, answer the following questions:
| Group No. → | 1 | 2 | 13 | 14 | 15 | 16 | 17 | 18 |
| Period ↓ | ||||||||
| 2 | A | B | ||||||
| 3 | E | D | F | C |
Write the molecular formula of the compound formed by the combination:
A and F
Define groups of modern periodic table.
1H2 is an isotope of hydrogen. In the modern Periodic Table it will ______.
Answer the following in respect of element \[\ce{_16^32S}\].
To which group and period does it belong?
Give reason for the following:
Inert gases do not form ion.
