Final answer:
The number of protons in one atom of an element determines the atom's atomic number and the number of electrons determines the chemical properties an element.
Step-by-step explanation:
The number of protons in one atom of an element determines the atom's atomic number, and the number of electrons determines the chemical properties of an element. In a neutral atom, the number of protons is equal to the number of electrons, which means each element has a characteristic number of electrons equal to its atomic number.
The atomic number is fundamental in distinguishing one element from another, as each element has a unique number of protons in its atoms.
For example, an atom with six protons is identified as carbon and has the atomic number 6. In electrically neutral atoms, the number of electrons will also be six. However, if an atom has gained or lost an electron, it becomes an ion with a positive or negative charge, affecting the atom's chemical properties.