Advertisements
Advertisements
प्रश्न
The symbols of the elements cobalt, aluminium, helium and sodium respectively written by a student are as
follows. Which symbol is the correct one ?
विकल्प
CO
AL
He
So
Advertisements
उत्तर
He
He is the correct symbol of helium.
APPEARS IN
संबंधित प्रश्न
Explain the terms 'valency' and 'variable valency'.
Give two examples of the following:
Liquid + Liquid mixture:
Match the non-metallic elements – with their correct symbols. Non-metallic elements are:
| Non-Metallic elements | Symbol |
| (a) Carbon | (1) O |
| (b) Chlorine | (2) I |
| (c) Oxygen | (3) Si |
| (d) Phosphorus | (4) C |
| (e) Hydrogen | (5) Cl |
| (f) Nitrogen | (6) P |
| (g) Iodine | (7) F |
| (h) Bromine | (8) H |
| (i) Fluorine | (9) S |
| (j) Silicon | (10) Br |
| (k) Sulphur | (11) N |
Give a reason why elements are tabulated in a table called the ‘Periodic table’.
Match the symbols of non-metallic elements with their correct combining power or capacity.
(a) O
(b) S
(c) Cl
Combining power or capacity A : 3; B : 2; C : 1. (negative valencies)
State the type of element for the following:
Carbon
Give the symbol of the following element:
Phosphate
Write the radical of the following valency:
Oxygen
Give the formula of the following acid:
Nitric
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).
Nitride
