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प्रश्न
Define periods of modern periodic table.
उत्तर
The horizontal rows are called periods. The periodic table contains seven periods.
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संबंधित प्रश्न
Fill in the following blank with suitable word:
Group 1 elements are called ...............
Give two example of group 18 elements.
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.
The atomic numbers of four elements P, Q, R and S are 6, 8, 14 and 16 respectively. Out of these, the element known as metalloid is:
(a) P
(b) Q
(c) R
(d) S
How would the tendency to lose electrons change as we go from left to right across a period of the periodic table?
How does the chemical reactivity of alkali metals vary on going in group 1 of the periodic table?
Name two elements in Inert gas.
State the modern periodic law for classification of elements. How many (i) groups and (ii) periods are there in the modern periodic table?
From the standpoint of atomic structure, what determines which elements will be the first and which the last in a period of the periodic table?
How does number of (i) valence electrons (ii) valency; vary on moving from left to right in the second period of a periodic table?
Two elements P and Q belong to the same period of the modern periodic table and are in group 1 and group 2, respectively. Compare the following characteristics in the tabular form.
- Number of electrons in their atoms
- Their tendency to lose electrons
- Their metallic characters
- Formation of their oxides
- Formulae of their chlorides
Give the symbol and valency of the following element and radical.
Magnesium
Give the symbol and valency of the following element and radical.
Bicarbonate
Give the chemical formula of sodium bicarbonate
Give the chemical formula of sodium sulphite
Give the chemical formula of carbonic acid
The d-block elements are called as _______ elements.
Find the odd one out and give its explanation.
To the left of the zig-zag line in the periodic table are the metal elements.
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:
Group 17 - Group 18
Explain structure of modern periodic table in short.
State any five features of modern periodic table.
______ and ______ are called inner transition elements.
The inert gas which lies in the third period is ______
What is the symbol of the element Tungsten?
Which of the given elements A, B, C, D and E with atomic number 2, 3, 7, 10 and 30 respectively belong to the same period?
Arrange the following elements in the increasing order of their metallic character
| Mg, | Ca, | K, | Ge, | Ga |
An element X which is a yellow solid at room temperature shows catenation and allotropy. X forms two oxides which are also formed during the thermal decomposition of ferrous sulphate crystals and are the major air pollutants.
- Identify the element X
- Write the electronic configuration of X
- Write the balanced chemical equation for the thermal decomposition of ferrous sulphate crystals?
- What would be the nature (acidic/ basic) of oxides formed?
- Locate the position of the element in the Modern Periodic Table.
Choose an element from period 3 of modern periodic table that matches the description given below in instance. Give a reason for your choice.
It has same valency as Lithium.
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:
E and B
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 |
Which of the element is a Noble gas?
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 |
Which of the element is a Metalloid?
Give the criteria on the basis of which elements are placed (i) in a group and (ii) in a period in the modern periodic table. The atomic number of an element is 16. According to the criteria, in which group and period it should be placed?
Define groups of modern periodic table.
An element has 2 electrons in its N shell.
State its position in periodic table.
Answer the following in respect of element \[\ce{_16^32S}\].
Give its formula with hydrogen.
Match the atomic number with the following:
An element of group 2.
