Can atoms of two different elements have the same atomic number or mass number? Why or why not?

Question

Can atoms of two different elements have the same atomic number or mass number? Why or why not?

Answer 1

Yes  and no.

It happens with the isotopes.

What is atomic number? It is the number of protons and neutrons in the nucleus, right?

What is the atomic number of Carbon? It is twelve

What is the atomic number of an atom of Carbon 14 (it has 6 protons and 8 neutrons)? It is 8+6=14

What is the atomic number of Silicon? It is 14

So an atom of Silicon and an atom of C14 have the same atomic number, and they are different elements.

The first part is: YES

The second part: Can two different elements have the same mass number? The answer is NO, why? because to have the same mass number you need to have the SAME number of protons, neutrons, and electrons, and if you have the SAME number of protons, neutrons, and electrons, then you cannot be a different element.

The second part is NO.

Hope this helps.

Answer 2

Two different elements can NOT have the same atomic number because atomic number(the number of protons in the nucleus). However you can have an element such as carbon 14, which is heavier than oxygen, because it has 6 Neutrons that outwiegh a single proton.  So basically smaller elements than the one in question, can have an isotope that can out weigh a heavier element.

Answer 3

Atoms of two different elements, by the definition of an element, MUST have different atomic numbers. We define the element helium, for example, to be the atoms that have 2 protons, or atomic number (Z) = 2.

Two atoms of different elements can certainly have the same mass number, though it is much more common in larger atoms. For example, the isotope 3He has 2 protons and 1 neutron, mass number = 3. 3H has 1 proton and 2 neutrons, mass number = 3.

One important note is that two different atoms, even if they have the same mass number, are extremely unlikely to have the exact same "mass" - this is because they have different binding energies, and invoking the classic "e=mc^2", different binding energies have different masses.

Answer 4

Not they cannot. Because they are two different elements,... you answered your own question,... kinda.... Silly billy!!!