The concentration may be expressed as % m/m, this is the mass of ions in 100 mass units of solution, whose formula is:
% m/m = [mass of ions / mass of solution]*100
Then,
%m/m = [8.5*10^ -3 grams of calcium ions] / [490 grams of solution] * 100 =
% m/m = 1.74 * 10^ -5 %
Answer: 1.74 * 10 ^ -5 %
The gastric chief cells of the stomach secrete enzymes for protein breakdown (inactive pepsinogen, and in infancy rennin). Hydrochloric acid activates pepsinogen into the enzyme pepsin, which then helps digestion by breaking the bonds linking amino acids, a process known as proteolysis.
They are considered the basic units of matter because all mass is made of atoms.
Answer:
True
Explanation:
The physical changes are reversible in most cases and these changes are not the chemical changes which means that it is only the change in its state not in their nature. Just take the example of water, on cooling it becomes solid and change in color can be seen which is white in solid form and colorless in liquid form. This is also reversible and is a physical change. This means that physical changes can be identified at macroscopic level. Hence the answer is true.
