Answer:
<em><u>spontaneous composition</u></em> is the ingnition
of the substance due to the repid oxidation of its on material.
There is no requirement of heat of external sources.
<em><u>Rapid composition</u></em> on the other hand release large amount of heat and light energy.
Explosion and the firecracker is the best example of Rapid composition.
Answer:
265.2amu
Explanation:
Given parameters:
Atomic mass = 254.9amu
Abundance of isotope 1 = 72%
Atomic mass of isotope 1 = 250.9amu
Abundance of isotope 2 = 100 - 72 = 28%
Unknown:
Atomic mass of isotope 2 = ?
Solution:
To find the atomic mass of isotope 2, use the expression below:
Atomic mass = (abundance of isotope 1 x atomic mass of isotope 1) + (abundance of isotope 2 x atomic mass of isotope 2)
Now insert the parameters and find the unknown;
254.9 = (0.72 x 250.9) + (0.28 x Atomic mass of isotope 2)
254.9 = 180.648 + 0.28x atomic mass of isotope 2
254.9 - 180.648 = 0.28x atomic mass of isotope 2
74.25 = 0.28 x atomic mass of isotope 2
Atomic mass of isotope 2 = 265.2amu
Answer:
132 amu
Explanation:
ammonium sulphate is 
to calculate molecular weight we need
atomic weight of the element of the compound
here ammonium sulphate is formed by two elements
2 nitrogen , 8 hydrogen , 1 sulphur amd 4 oxygen
atonomic number of nirogen is 14 , hydrogen is 1 , sulphur has 32 and oxygen has 16
so lets calculate molecular weight of ammonium sulphate
2*14 + 8*1 + 1*32 + 4*16
28 + 8 + 32 + 64
132 amu
