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.
Those would be called indicators , simply google them and you should find many. I'll leave some examples "bromophenol blue" "Methyl red" and "phenol red".
Im not sure but milk is liquid, helium is gas, granite is solid, oxygen is gas, steel is solid, and gasiloine is liquid.
Answer:
c. 2NH₃ + 2H₂O + Cu²⁺ → Cu(OH)₂(s) + 2NH₄⁺
Explanation:
A net ionic equation is a chemical equation that list only the species that are involved in the reaction.
The reaction of ammonia with copper(II) sulfate CuSO₄ in water is:
2NH₃ + 2H₂O + CuSO₄ → Cu(OH)₂(s) + 2NH₄⁺ + SO₄²⁻
In an ionic equation, salts are written as ions, that means CuSO₄ must be written as Cu²⁺ + SO₄²⁻. That is:
2NH₃ + 2H₂O + Cu²⁺ +<u> SO₄²⁻</u> → Cu(OH)₂(s) + 2NH₄⁺ + <u>SO₄²⁻</u>
As in a net ionic equation you must list only the species involved in the reaction (The underlined species don't react), the net ionic equation is:
<em>c</em>. <em>2NH₃ + 2H₂O + Cu²⁺ → Cu(OH)₂(s) + 2NH₄⁺</em>
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I hope it helps!