the number of protons in the nucleus of an atom\nphysical properties of matter\natomic number\nvalence…

the number of protons in the nucleus of an atom\nphysical properties of matter\natomic number\nvalence electrons\nneutron

the number of protons in the nucleus of an atom\nphysical properties of matter\natomic number\nvalence electrons\nneutron

Answer

Answer:

B. atomic number

Brief Explanations:

The atomic number of an element is defined as the number of protons in the nucleus of an atom of that element. Physical properties of matter refer to characteristics like density, color etc. Valence - electrons are outer - shell electrons involved in bonding. Neutrons are neutral particles in the nucleus.