All of the above are chemical reactions.
If that is a choice
Answer:
Nuclear fusion plays an important role in making elements that are heavier than helium.
Explanation:
Nucleosynthesis is the process by which new atomic nuclei are created from pre-existing nucleons (protons and neutrons) and nuclei. According to current theories, the first nuclei were formed a few minutes after the Big Bang, through nuclear reactions in a process called Big Bang nucleosynthesis.
In order to synthesize a new element, there must be a change in the number of protons. We should remember that elements are known by the number of their protons as it represents their atomic number.
Elements heavier than helium are formed by nuclear nucleosynthesis in which nuclear fusion plays a very crucial role as typified by the equations shown in the question.
<em>M CaCl₂: 40+(35,5×2) = 111 g/mol</em>
6,02·10²³ molecules ---------- 111g
X molecules --------------------- 75,9g
X = (75,9×<span>6,02·10²³)/111
X = <u>4,116</u></span><span><u>·10²³</u> molecules of CaCl</span>₂
:)
In ionic bond there is the formation of ions due to transfer of electrons from one atom<span> to </span>the other. Normally, at this link, there is an element that tends to yield electrons (metal-cation), and one that tends to receive electrons (not metal-anion).
Note: the Ionic bond is the only in the transfer of electrons<span>.</span>
are present in 
<u>Explanation:</u>
It is known that each mole of an element is composed of avagadro's number of molecules. So if we need to determine, we need to divide the number of molecules with the avagadro's number.
So,
As here 
molecules of carbon di oxide is given. So the moles in it will be
No. of moles of carbon dioxide = 
No. of moles = 
moles of carbon dioxide.
Thus,
of carbon dioxide are present in .
