A. The correctly balanced equation is that in which the number of atoms of a certain element at the left-hand side is similar to that in the right hand side or the reactant side and product side, respectively. From the given equation, the answer would be,
C. Cl2 + 2NaI --> 2NaCl + I2
B. In the given chemical reaction above, heat is emitted such that it appears in the product side of the equation. Hence, this is an example of a combustion reaction.
C. Similar with the reasoning in letter A, the answer to this item is,
B. 2H2 + O2 --> 2H2O
Answer:
The combining of light nuclei is called nuclear fusion.
Answer:
KE + PE = KE + PE
Explanation:
In a closed system, the mechanical energy of the system is constant.
Mechanical energy is given by the sum of kinetic energy and potential energy; mathematically:
U = KE + PE
where
KE is the kinetic energy
PE is the potential energy
This means that if we consider two situations, one at the beginning and one at the end, the value of U will not change if the system is closed; this means that the sum KE + PE will remain the same, so we can write:
KE + PE = KE + PE