What makes one atom or element different than another?

Answer 1

Different atoms either have a different number of protons(which makes them different elements) or a different number of neutrons (which makes them isotopes of the same element).

For example, hydrogen has one proton (and usually no neutrons) while helium has two protons (and usually two neutrons). However, hydrogen with one proton and two neutrons is called tritium(3H) while helium with two protons and one neutron is called helium-3 (3He).

Answer 2

Primarily the number of protons in the atoms nucleus (which is the same as the number of electrons it has).

Secondarily in the number of neutrons in the atoms nucleus (for isotopes).

Also it is the "surface" of the atom that gives it is unique chemical properties. The protons and neutrons are deep inside the atom and it is the electrons that form the "surface". Therefore it would be true to say that it is the electrons (their number and which electron shells are filled) that give atoms their properties and make one element different from another.

Answer 3

The core of an atom is comprised of neutrons and protons. While the number neutrons in an atom may vary in an element, the number of protons must stay the same.

That means Hydrogen will always have 1 proton, helium will have 2 protons, lithium will have 3 protons, ect...

T>o sum it up: Its the number of protons in the core of an atom.

Answer 4

The number of protons in the nuclei of their atoms. This is the atomic number of an element and each element has its own unique atomic number.

Answer 5

every atom has a unique number of protons, and proton number equals electron number.

Answer 6

the Atomic Mass and the number of protons and neutrons that the atom has

Answer 7

the number of neutrons, protons and electrons that they're made up of.