Solution :
Molar mass of 
is :
M = 6×12 + 6×1 g
M = 78 g
78 gram of contains 
molecules.
So, 89.5 gram of contains :
Now, from the formula we can see that one molecule of contains 2 hydrogen atom . So, number of hydrogen atom are :
Hence, this is the required solution.
The following does NOT indicate that a chemical change
may have taken place is fracture formation. A chemical change happens when the
substance changes its physical state and composition resulting from a chemical
reaction. This chemical reaction may either give off or absorb energy. A change
in color is a chemical change. For example, litmus paper turns to red when
placed in an acid solution. Production of gas is a chemical change. For
example, adding hydrochloric acid to the tiles of the bathroom gives a hissing
sound with gases given off. Formation of a precipitate is also a chemical
change. Change in shape is not a chemical change.
<span> </span>
The correct answer is option B. Dirty water is a mixture of solid particles and liquid. It is both a mixture and pure substance.
The dirty water sample has both gravel and liquid water in it. After filtration the gravel is removed so the water sample looks clearer than before filtration. Liquid water is a pure substance because it is a compound that is made up of elements hydrogen and oxygen. Now the gravel is only physically combined with the liquid water, thus giving the water sample properties of a mixture. And like any mixture, gravel is physically separated through filtration from the liquid water.
Thus the water sample of the chemists is both a mixture and pure substance.
Correct answers:
<span>Nuclear fission and fusion both affect the nucleus of an atom.
</span><span>The final products of fission and fusion are elements that are different than the original.
</span><span>Fission occurs mostly with elements heavier than lead on the periodic table.</span>
