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प्रश्न
Write the merits of the modern periodic table over Mendeleev’s Periodic table
उत्तर
1) Elements are arranged on the basis of increasing atomic number which is more fundamental.
2) Isotopes of an element can be placed along with parent element.
3) It explains periodicity of properties of elements configuration.
4) Lanthanides and actinides are placed separately.
5) Anomalous pairs of elements like Ar and K having same atomic mass could be justified
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संबंधित प्रश्न
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?
State modern periodic law.
Fill in the following blank with suitable word:
Group 1 elements are called ...............
Give two example of group 1 elements.
How does the chemical reactivity of the halogens vary on going in group 17 of the periodic table?
State whether the following statement is true or false:
On going down in a group of the periodic table, the number of valence electrons increases.
State how the valency of elements varies in a period of the periodic table?
(b) What is the number of elements is 3rd period, the modern periodic table?
What are the groups in a periodic table? Give two characteristics of each.
Consider the following elements:
20Ca, 8O, 18Ar, 16S, 4Be, 2He
Which of the above elements would you expect to be:
(i) very stable?
(ii) in group 2 of the periodic table?
(iii) in group 16 of the periodic table?
What are horizontal rows and vertical columns in a periodic table known as?
Name two elements in Alkali metals.
Name two elements in Inert gas.
Answer the following in respect of element `31/15 P `
To which group and period does it belong?
How will the tendency to gain electrons change as we go from left to right across a period? Why?
How many periods and groups are there in the modern periodic table?
Name an element of group 18 which can form compounds.
The horizontal rows in a periodic table are called _____.
An element A has 2 electrons in its fourth shell. State its electronic configuration.
Give the symbol and valency of the following element and radical.
Hydroxide
Give the symbol and valency of the following element and radical.
Sulphate
Give the chemical formula of sodium nitrate
Give the chemical formula of ammonium sulphate
p-block is composed of groups 1 and 2.
Distinguish between:
Group 17 - Group 18
Noble gases belong to______ group of the periodic table.
Which of these belong to the same period?
| Element | A | B | C |
| Atomic number | 2 | 10 | 5 |
The elements A, B, C, D and E have atomic number 9, 11, 17, 12 and 13 respectively. Which pair of elements belong to the same group?
The element with atomic number 14 is hard and forms acidic oxide and a covalent halide. To which of the following categories does the element belong?
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 a similar structure to diamond.
The maximum number of electrons that can be accommodated in s, p,d, and f subshells are ______.
Explain the position of hydrogen in the periodic table.
An element belonging to 3d series of modern periodic table has spin magnetic moment = 5.92 B.M. in +3 oxidation state. The atomic number of elements are ______.
An element has 2 electrons in its N shell.
State its position in periodic table.
An element has 2 electrons in its N shell.
Is it a metal or a non-metal?
Answer the following in respect of element \[\ce{_16^32S}\].
To which group and period does it belong?
Match the atomic number with the following:
A rare gas.
