<span>It changes with new evidence.
The example shows that science changes with new evidence. Science can not change with common beliefs because first of all beliefs should be proved and become evidence. Second, science is not fixed because of the scientific method and experimentation, which is a phase of the scientific method.
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Answer:- Oxidation number of Cl does not change as it is -1 on both sides.
Explanations:- oxidation number of Mg on reactant side is 0 as it is in its elemental form(not combined with another element).
Oxidation number of hydrogen in its compounds is +1, so if H is +1 in HCl the oxidation number of Cl is -1 as the sum has to be zero.
On product side, Mg oxidation number is +2 as the oxidation number of alkaline earth metals in their compounds is +2.
Two Cl are present in magnesium chloride, so if Mg is +2 then Cl is -1.
Oxidation number of H on product side is 0 as it is present in its elemental for, 
,
So, it is only chlorine(Cl) whose oxidation number does not change for the given equation.
C The number and types of bonds within the molecule.
Explanation:
In a molecule, the number and types of bonds present determines the amount of available energy therein.
When bonds are broken or formed, energy is usually released.
- Elements combine with one another in order to attain stability in this state.
- Through this process, they form bonds by attraction.
- Where atoms exchange their valence electrons by losing or gaining it, electrovalent bonds form.
- In covalent molecules, electrons are usually shared between atoms.
- An attraction result from this type of interaction.
- The bond formed stores energy in the process.
- When bonds are broken, energy is usually released. The energy accrues when the bond was being formed.
- In molecules, we have covalent bond.
Learn more:
Bond brainly.com/question/7213980
Covalent bonds brainly.com/question/5258547
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