Question

which statement is true about all the atoms of a given element?
a they have the same number of neutrons.
b they can have a different number of protons.
c they are the same size as the atoms of all other elements.
d they all have the same number of protons.

Explanation:

• Option a: Atoms of the same element can have different numbers of neutrons (isotopes).
• Option b: The number of protons defines an element. All atoms of a given element must have the same number of protons.
• Option c: Atoms of different elements have different sizes.
• Option d: The atomic number (number of protons) is unique to each element. All atoms of a given element have the same atomic number, i.e., the same number of protons.

Answer:

d. They all have the same number of protons.