Advertisements
Advertisements
प्रश्न
Fill in the blank
There are ______ groups and ______ periods in the modern form of periodic table.
उत्तर
There are 18 groups and 7 periods in the modern form of periodic table.
APPEARS IN
संबंधित प्रश्न
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'.
Which element has a total of two shells, with three electrons in its valence shell?
The following table shows the electronic configuration of the elements W, X, Y, Z:
| Element | w | x | y | z |
| Electronic configurations |
2, 8, 1 | 2, 8, 7 | 2, 5 | 1 |
Answer the following questions based on the table above:
1) What type of Bond is formed between :
a) W and X
b) Y and Z
2) What is the formula of the compound formed between :
a) X and Z
b) W and X
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]
Complete the following sentences
The similarities in the properties of a group of elements are because they have the same …………………
Taking into consideration the period of the elements given below, answer the following questions:
| Elements | Atomic Radius (pm) |
| O | 66 |
| B | 88 |
| C | 77 |
| N | 74 |
| Be | 111 |
| Li | 152 |
- Arrange the above elements in decreasing order of their atomic radii.
- State the period to which the above elements belong.
- Why this arrangement of elements is similar to the above period of modern periodic table?
- Which of the above elements have the biggest and the smallest atom?
- What is the periodic trend observed in the variation of atomic radius while going from left to right within a period?
How could the atomic radius of a noble gas be compared with the other elements in a period?
Arrange the following as per instruction given in the bracket.
Mg, Cl, Na, S, Si (decreasing order of atomic size)
Name and state the following with reference to the elements of the first three periods of the periodic table.
Alkaline earth metal in period 3.
Name or state following with reference to the element of the first three periods of the periodic table.
A covalent compound formed between an element in period 1 and a halogen.
