Question

Which subatomic particle plays the greatest part in determining the properties of an element?

Answer 1

The subatomic particle that plays the greatest role in determining the physical and chemical properties of an element is the electron. The electron has  symbol e− or β− with a negative elementary electric charge. Thank you for posting your question here. I hope the answer helps. 

Answer 2

Answer:

Proton

Explanation:

We know that atomic number is equal to proton number.

If we know the proton number then we  can determine the atomic number  and number of electrons.

Because number of protons=Number of electrons.

If we know that atomic number then we can determine the electronic configuration.

We can determine valency of an element by determining outer  electronic configuration.

If we know electronic configuration then we can know that the element from which period and group belongs.

Hence, the proton particle plays the greatest part in determining the properties of an element.