Answer fast needed - Science - The Fundamental Unit of Life

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Answer fast needed

Anita Gupta · Accepted Answer

Dear student, (iv) The correct option is c According to the law of
constant proportion , a chemical substance always contains the same
elements in a fixed proportion by mass, irrespective of its source
The law of constant proportion is also known as the law of definite
proportion This law, which was introduced by Proust, stated that
â€˜in a compound, the elements are always present
in definite proportions by massâ€™ For example:
Pure water obtained from any source (well, river, lake, or sea) and
from any country (India, Russia, America, etc ) will always contain
two hydrogen atoms and one oxygen atom Hydrogen and oxygen
respectively combine together in the ratio of 1:8 by mass to form
water The ratio by the number of atoms for water will always be H :
O = 2 : 1 Thus, 18 g of water contains 2 g of hydrogen and 16 g of
oxygen Similarly, in ammonia, nitrogen makes up 14/17 of the mass
of ammonia while hydrogen makes up the remaining 3/17 of the mass
Irrespective of the source from which ammonia is obtained, it will
always contain nitrogen and hydrogen in the ratio of 14: 3 by mass
Thus, 17 g of ammonia contains 14 g of nitrogen and 3 g of
hydrogen, and 34 g of ammonia contains 28 g of nitrogen and 6 g of
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