Is elemental phosphorus dull or high luster?

Each element can usually be classified as a metal or a non-metal based on their ... They are usually dulland therefore show no metallic luster and they do not reflect ... Dull, Brittle solids; Little or no metallic luster; High ionization energies; High ...

D)can be increased in a closed system

Because electrons have negligible mass, to account for the mass of the isotope, there must be 16 neutrons, 16 neutrally charged, massive, fundamental particles present in the sulfur nucleus. and thus finally, if we have the 32s2− ion, there are 18 electrons, 16 protons, and 16 neutrons.