Some studies has shown that peppermint odor increases people’s mental sharpness, especially when they solve math problems. which best describes how this could be a valid scientific claim?

a if it is tested in a controlled setting with repeated results
b if the test is published on wikipedia
c if the scientist was previously peer reviewed
d if the math problems are easy problems

A if it is tested in a controlled setting with repeated results

Explanation:

A scientific claim is a statement which includes the results which are obtained after the implementation of experimental methodology and reasoning for the cause of a particular natural phenomena or event. Relevant facts and evidences supports the claim.

The results are only considered valid when the repeated trials using the same methodology are done under controlled conditions.

answer: -

reaction:

na + cl ⇌ nacl

balanced chemical equation:

na + 2cl ⇌ nacl2

sodium + clorine goes to form sodium chloride (table salt).

the product is nacl2.

and the reactants are na and cl.

(note: if you don’t know what ⇌ means, read below: -

⇌(double head arrow) means reversible reaction).

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.