Question

Given the fluorine atom has mass number 19 and electronic configuration 2,7. Find the number of protons, number of neutrons, number of electrons, and mass number.

Answer 1

• The electronic configuration of fluorine is given as 2,7.
• Electronic configuration, also called electronic structure, is the arrangement of electrons in energy levels around an atomic nucleus. Thus the number of electrons=(2+7)=9.
• The number of electrons in a neutral atom is equal to the number of protons. Hence the number of protons will be equal to 9.
• Atomic number of an element will be equal to the number of protons in an atom. Thus atomic number=9.
• Given the mass number=19.
• Mass number is the sum of the number of protons and neutrons.
• Hence number of neutrons= mass number-number of protons=(19-9)=10.