Answer:
Hypothesis
Explanation:
Refer to a trial solution to a problem as a hypothesis, often called an "educated guess" because it provides a suggested outcome based on the evidence.
<u>First Symbol </u>: Cobalt (Co)
Its Group Number - 9
Its Period Number - 4
Its Family Name - Transition Metal
<u>Second Symbol</u> : Silicon (Si)
Its Group Number - 14
Its Period Number - 2
Its Family Name - Semiconductor
<u>Third Symbol</u> : Astatine (At)
Its Group Number - 17
Its Period Number - 6
Its Family Name - Halogen
<u>Fourth Symbol </u>: Magnesium (Mg)
Its Group Number - 2
Its Period Number - 3
Its Family Name - Alkaline Earth Metal
<u>Fifth Symbol</u> : Xenon (Xe)
Its Group Number - 18
Its Period Number - 5
Its Family Name - Noble Gas
J.J. Thomson discovered the electron by noticing that a beam of particles could be influenced by an electric or magnetic force.. That is option B.
<h3>What is an electron?</h3>
An electron can be defined as the part of an atom that is negatively charged and is found revolving round the nucleus of an atom.
J.J. Thomson was the scientist that discovered electrons through subjecting two oppositely-charged electric plates around the cathode ray.
He noticed that the particles where deflected by both the magnetic and electric fields.
Learn more about cathode rays here:
brainly.com/question/4441361
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