Answer: D) helium.
Explanation:
Nuclear fission is a process which involves the conversion of a heavier nuclei into two or more small and stable nuclei along with the release of energy.

Nuclear fusion is a process which involves the conversion of two small nuclei to form a heavy nuclei along with release of energy.
Example: 
Thus when deuterium and tritium , the two isotopes of hydrogen are fused, a heavier nuclei helium is being formed from two smaller nuclei releasing a neutron.
Carbon is the one and only element to make a molecule organic.
Answer:
30moles of SiO₂
Explanation:
Given parameters:
Number of moles of O₂ = 30moles
Unknown:
Number of moles of SiO₂ = ?
Solution:
To solve this problem, we need to write the reaction expression:
Si + O₂ → SiO₂
The reaction is balanced;
1 mole of O₂ will produce 1 mole of SiO₂
30mole of O₂ will produce 30moles of SiO₂
Answer:
The answer to your question is Mg loses its valence electrons and acquire a positive charge (Mg⁺²).
Explanation:
Valence electrons are important for an element to attach to another one, metals lose these electrons while nonmetals gain electrons to complete the octet rule.
Magnesium is a metal that loses these electrons so when it becomes an ion Magnesium will have a positive charge Mg⁺².
I believe the answer is D.