Question

please help me i will give medal

Answer 1

Which statement best explains how isotopes can have different masses and still be the same element?

A.
The quantity of protons identifies the element and cannot change; therefore, the neutron amount changes, ultimately changing the overall mass of the atom.

B.
The quantity of protons identifies the element but changes if the mass of the isotope differs from what is shown on the periodic table.

C.
The sum of the electrons and neutrons equals the isotope's mass with the proton amount being given by the atomic number.

D.
The sum of the protons and electrons equals the mass of the isotope, and the neutron amount is equal to the atomic number.

Answer 2

A...

Answer 3

B all the way
proton # = atomic #, each atom of an element has a set amount
electrons in a neutral atom = the proton #
neutrons can differ in the amount present and different set amounts leads to isotopes
most isotopes that are uncommon are radioactive resulting from nuclear decay, these isotopes don't last long since they eventually through a series of decay steps end up as a stable isotope of lighter elements, hence they are less common

Answer 4

B is not correct, the number of protons does determine which element an atom is, but the different masses of isotopes of a given element are due to different numbers of neutrons. A is the right answer.