Atoms of different elements have A. Same atomic number and same electronic configuration B. Different atomic number and same eletronic configu-ration C. Different atomic number and different number of valence electrons D. Same number of electrons and neutrons

The correct answer is C. Different atomic number and different number of valence electrons.

Atoms of different elements have different atomic numbers. The atomic number is the number of protons in the nucleus of an atom. The

number of protons determines the chemical element of the atom. For example, all atoms with 6 protons in their nucleus are carbon atoms.

Atoms of different elements also have different numbers of valence electrons. Valence electrons are the electrons in the outermost shell of an atom. The number of valence electrons determines the chemical properties of an atom. For example, all atoms with 1 valence electron are metals.

Option A is incorrect because atoms of different elements have different atomic numbers.

Option B is incorrect because atoms of different elements have different numbers of valence electrons.

Option D is incorrect because

atoms of different elements have different numbers of protons and neutrons. The number of neutrons is the number of subatomic particles in the nucleus of an atom that are not protons. The number of neutrons does not affect the chemical properties of an atom.