Answer:
Option 1 and 3 are correct.
Explanation:
Buffer solution is the solution which resists the change in the magnitude of the pH when small additions of either acid or base is added. Buffer solutions consist of weak acid and its conjugate base usually which are mixed in relatively equal and large quantities.
Hence,
Option 1. is correct because acetic acid is a weak acid and sodium acetate is the conjugate base of it which are mixed in equal concentrations.
Option 2. is incorrect because HCl and NaCl are both strong acid and salt respectively and will not form a buffer.
Option 3. is correct which is the definition of a buffer solution.
Option 1 and 3 are correct.
The only cause we know of that could shift the spectrum of a source toward longer wavelengths isthe source moving away from us. That's how we interpret the red shift when we see it, and that's where the whole idea of the expanding universe comes from. But ... just like gravity and the Earth going around the sun ... it can't be proved, so it's "only a theory".
Answer:
the atom
Explanation:
The bread and cheese separately represent the atom because both bread and cheese are different from one another and we cannot assume it as a molecule because molecules formed when the group of atoms combine together by making bonds with each other and we know that bread and cheese did not make bonds with each other, they only attached, so we called them atoms not molecule.
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