Fill in the following blanks with suitable words : (a) Light travelling along a normal is ___ refracted. (b) Light bends when it passes from water into air. We say that it is ___.
Fill in the following blank with a suitable word: The amount of heat produced by burning a unit mass of a fuel completely is known as its ................ value.
Fill in the blanks with suitable words :
Detergents contain ______ like fertilizers.
mercury is a _______ substance.