Question

ns, and isotopes review quiz
9
f
fluorine
18.99
which of the following statements are true regarding this element?
there are 9 protons in the nucleus
there are 9 electrons in a neutral atom
there are 19 neutrons in the nucleus

Explanation:

Step1: Identify atomic number meaning

The atomic number of an element is the number of protons in the nucleus. For fluorine (F), the atomic number is 9, so there are 9 protons in the nucleus.

Step2: Recall electron - proton relationship in neutral atoms

In a neutral atom, the number of electrons is equal to the number of protons. Since fluorine has 9 protons, a neutral fluorine atom has 9 electrons.

Step3: Calculate number of neutrons

The mass number (approximate) is 19 (from the rounded - off atomic mass 18.99). The number of neutrons = mass number - number of protons. So, number of neutrons = 19 - 9=10, not 19.

Answer:

There are 9 protons in the nucleus, There are 9 electrons in a neutral atom