Answer:
If the scientist makes a statement so it is 100 % valid.
Step-by-step explanation:
Once scientists believe something to be true, they will say so with 100% certainty. This statement is true because the statements of the scientist is not based on theories. Scientist make any statement after performing many experiments in order to verify the statement. So if the scientist will say about something with 100 percent certainty so it is considered as valid because the statement goes through from a number of experiments.