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प्रश्न
What is the main characteristic of the last elements in the periods of a periodic table? What is the general name of such elements?
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उत्तर
The last elements of each period have their outermost shell complete, i.e. 2 or 8 electrons. Main characteristics of the last element in each period of the Periodic Table are:
- They have valency equal to zero.
- They react under very special condition otherwise they don't react.
- They have stable gas electronic configuration.
- The general name is inert gases or noble gases.
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संबंधित प्रश्न
Write the name from the description.
The period with electrons in the shells K, L, and M.
Match column A with column B.
|
Column A |
Column B |
|
(a) Element short by 1 electron in octet |
(i) Transition elements |
|
(b) Highly reactive metals |
(ii) Noble gases |
|
(c) Non-reactive elements |
(iii) Alkali metals |
|
(d) Elements of groups 3 to 12 |
(iv) Alkaline earth metals |
|
(e) Radioactive elements |
(v) Halogens |
|
(f) Elements with 2 electrons in the outermost orbit |
(vi)Actinides |
Write a short note on the following type of element –
transition elements
If the electronic configuration of an element is 1s2 2s2 2p6 3s2 3p1’then it will
occupy ______ block of the periodic table.
Group 1 (except hydrogen) elements are called alkali metals.
d-block elements are called transition elements.
Assertion (A): Group 2 elements in the modem periodic table are called alkaline earth metals.
Reason (R): The oxides of group 2 elements produce alkaline solutions when they are dissolved in water.
Assertion (A): Noble gases are chemically inert in nature.
Reason (R): Noble gases have stable electronic structures.
Match the columns:
| Column ‘A’ | Column ‘B’ |
| Manganese | (a) Metal |
| (b) Non-metal | |
| (c) Transition metal |
Answer the following questions related to the modern periodic table.
How are elements placed around the zig-zag line in the p-block of the periodic table?
