Question

question
the chemical properties of every element are determined by
answer
the number of protons in the nucleus
the atomic weight of the atom
the number of protons and neutrons in the nucleus
the number and arrangement of electrons in the outer energy level
i dont know yet

Explanation:

The chemical behavior of an element is related to its ability to gain, lose, or share electrons. The number and arrangement of electrons in the outer - most energy level (valence electrons) determine how an element will react with other elements. Protons determine the element's identity, atomic weight is related to protons and neutrons and is more about mass rather than chemical properties.

Answer:

the number and arrangement of electrons in the outer energy level