Similarly, lesser the density, greater will be the velocity of sound.
|Sodium||Sodium chloride, Sodium nitrate, Sodium carbonate (Washing soda Na2CO3 .10 H2O) and Bora|
|Potassium||Nitre (Potassiumnitrate), Pearl ash (Potas sium carbonate), Pota-ssium cyanide, Carnallite (Kcl . MgCl2 . 6 H2O)|
|Silver||Argentite, Stephenite, Horn silver, Lunar caustic (silver nitrate)|
|Magnesium||Magnesite (MgCo3), Dolomite (MgCo3 . CaCo3), Epsomite (MgSO4 . 7H2O), Asbestos [CaMg2 (SiO3)4]|
|Calcium||Iceland spar, Gypsum [CaSO4 . 2 H2O), Flurospar (CaF2), Fluorapatite [3 Ca3 (PO4)2], Plaster of Paris [(CaSO4)2 . H2O]|
|Zinc||Zinc blend, Calamine, Zincite.|
|Aluminium||Bauxite (Al2O3 . 2 H2O), Corondum (Al2O3),Cryolite (Na3 AlF6).|
|Tin||Tin stone or cassiterite (SnO2)|
EHF (Extremely High Frequency)
SHF (Super High Frequency)
UHF (Ultra High Frequency)
VHF (Very High Frequency)
HF (High Frequency)
LF (Low Frequency)
0.1 to 1 cm.
1 to 10 cm.
10 to 100 cm.
1 to 10 m.
10 to 100 m.
longer than 100 m.
Examples of Refraction—
A stick or spoon dipped in water appears short.
A coin dipped in water appears to be raised.
Twinkling of stars.
Sparkling of a diamond.
Glittering of air bubble in water.
Formation of ‘mirage’ and ‘looming’.
DNA (Deoxy-Xibose Nucleic Acid)
RNA (Ribose Nucleic Acid)
(i) Double stranded in the form of helix.
(ii) Four nitrogenous bases are Adenine, Guanine,
(iii) With some exceptions (as in certain viruses), it is genetic carrier.
(i) Single stranded and linear;
(ii) Thiamine is replaced by Uracil.
(iv) Present in nucleus as well as in cytoplasm.
Defect of vision
Type of defect
1. Long-sightedness or Hypermetropia
2. Short-sightedness or Myopia
3. Astigmatism (Images are formed at varying distances from their retina)
Eye ball becomes smaller or focal length of the eye lens is large.
Elongation of eye ball or focal length of the eye lens is small.
Eye ball is not curved equally in all directions