Question

How are two atoms of the same element alike?

Answer 1

"Two atoms of the same element contain the same number of protons.
They can have different numbers of neutrons, but then they are isotopes of the element.
If the number of electrons is different from the number of protons, they are ionsof the element."

Answer 2

An isotope only differs in the number of neutrons it has. All isotopes of an element have the same atomic number (the number of electrons/protons), therefore, they have the same number of electrons/protons and therefore similiar chemical properties.