Heredity and Variation — Science STD 9 — Question

Fill in the blanks in the following statements:
The total number of protons and neutrons in the nucleus of an atom is called its __________.

Fill in the following blanks with suitable word:
Echoes are caused by the ______ of sound.

Fill in the following blanks with suitable words:
A heterogeneous mixture of liquid and solid is conveniently separated by ___________.

The red blood cell count increases in the________ disease

Fill in the blanks in the following statements:
If the nucleus of an atom has atomic number 17, mass number 37 abd there are 17 electrons outside the nucleus, the number of neutrons in it is ____________.

Measles : Virus :: Ringworm : …………………………. .

Dengue : Virus :: Malaria : …………………………. .

________is used to make hard water soft.

Fill in the following blanks with suitable words:
The separation of liquids by fractional distillation is based o the difference in their __________.