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प्रश्न
Name the elements in the correct order of their increasing atomic numbers present in the first, second, and third short periods of the periodic table.
State which of the elements are –
- metallic
- non-metallic
- noble gases
in each of the periods 2 and 3.
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उत्तर
Names of elements of:
| Period first | Hydrogen | Helium |
| H | He |
| Period – 2 | Li | Be | B | C | N | O | F | Ne |
| Lithium | Beryllium | Boron | Carbon | Nitrogen | Oxygen | Fluorine | Neon |
| Period – 3 | Na | Mg | Al | Si | P | S | Cl | Ar |
| Sodium | Magnesium | Alummium | Silicon | Phosphorus | Sulphur | Chlorine | Argo |
- Metals: Li, Be, Na, Mg, Al
- Non-metals: C, N, O, F, P, S, Cl
- Noble – gases: Ne, Ar
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संबंधित प्रश्न
Write the number of periods the Modern Periodic Table has. State the changes in valency and metallic character of elements as we move from left to right in a period. Also state the changes, if any, in the valency and atomic size of elements as we move down a group.
In terms of electronic configurations, explain the variation in the size of the atoms of the elements belonging to the same period and same group ?
The correct increasing order of the atomic radii of the elements oxygen, fluorine and nitrogen is:
(a) O, F, N
(b) N, F, O
(c) O, N, F
(d) F, O, N
State whether the following statement is true or false
Similar electronic configuration is repeated after intervals of 2, 8, 8, 18 and 32.
Select the correct answer
Identify the metalloid
Choose the most appropriate answer from the following list of oxides which fit the description.
An amphoteric oxide: Al2O3 (shows both acidic and basic properties)
Arrange the following as per instruction given in the bracket
Na, K, Cl, S, Si (increasing ionisation potential)
Name and state the following with reference to the elements of the first three periods of the periodic table.
Metalloid in Period 3.
An element A has 2 electrons in its fourth shell. State:
its valency
Answer the following question:
State the four blocks of the modern periodic table based on the electronic configuration of elements.
