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प्रश्न
An atom of an element is denoted by a “symbol” Explain the meaning of the term ‘symbol’. State a reason for representing the following element by its symbol.
Helium by ‘He’
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उत्तर
Symbols: The short form or abbreviated name of the element (or radicals) The reason for representing the following element by their symbol is as follow:
Helium by He – First two letters of the name of Noble gases.
संबंधित प्रश्न
Give two symbols which have been derived from the " Latin names" of the elements.
A student wants to have 3.011 × 1023 atoms each of magnesium and carbon elements. For this purpose, he will have to weigh :
Match the noble gases – with their correct symbols:
| Noble gases | Symbols |
| (a) Helium | (1) Ar |
| (b) Neon | (2) Xe |
| (c) Argon | (3) Rn |
| (d) Krypton | (4) He |
| (e) Xenon | (5) Kr |
| (f) Radon | (6) Ne |
Match the symbols of – radicals – with their correct combining power or capacity, (valency).
(a) OH
(b) So4
(c) No3
(d) Co3
Combining power or capacity – A : 3; B : 2; C : 1. (negative valencies)
Elements are mainly classified into metals and non-metals. State six properties of metals which differ from non-metals.
Give the symbol of the following element:
Lead
Write the radical of the following valency:
Nitrate
Give the formula of the following gas:
Hydrogen chloride
Give the formula of the following gas:
Carbon monoxide
State whether the following ion or radical given below of a non-metallic element exhibits valency: 1–, 2– or 3–. (write the ion or radical with the correct valency).
Aluminate
