An atom contains protons and neutrons in the nucleus (though Hydrogen does not have neutrons) and electrons orbiting the nucleus.
The nucleus contains the mass.
the nucleus is the center of an atom that contains the positively charged protons and the neutrally charged neutrons. It contains most of the mass of the atom.
The nucleus, made up of protons and neutrons, contains most of an atom's mass.
It is the nucleus. It is the middle of the atom
only contains one atom
It contains protons and neutrons and no electrons.
this contains sodium and carbon
it only contains proton and neutron
A substance that contains only one type of atom is called an "element".
The question is somewhat vague. If the question were written as an atom contains seven electrons in the outermost energy level and that outermost shell is a p-shell then the atom is a halogen. If the atom contains seven electrons in the outermost energy level and that outermost shell is a d-shell or f-shell then the atom is a metal.
A molecule contains more than one atom.
A typical atom of iodine contains 74 neutrons.