How many protons are in an element with an atomic number or 8 and a mass number of 18?

Atomic structure and Isotopes Quiz - Quizizz. The mass number of an element that has 18 protons, 18 electrons, and 19 neutrons is The atomic number of an element that has 9 protons, 9 electrons, and 10 neutrons is

8 protons because protons are equal to the atomic number

Compound with sulfer  is bright red