Ascientist read about an experiment done by someone else. she does the same experiment in her lab to make sure it works.
this is an example of

The correct answer will be- repetition of the experiment to test the hypothesis

Explanation:

A scientific experiment is performed to test the hypothesis which checks whether the hypothesis is true or not true.

Testing the hypothesis is the key of the scientific investigation so the repetition of the experiments is done to check the validity of the hypothesis either by the same researcher who formulated the hypothesis or another researcher who check and verify the results.

Thus, the repetition of the experiment to test the hypothesis is the correct answer.

answer; i do believe the correct answer is (river); /// good luck

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g