Question

10
an atom of fluorine has the atomic number 9, and its mass number is 19 amu. which of the following shows an ion of fluorine?
four atomic structure diagrams labeled w, x, y, z
a. w
b. x
c. y
d. z

Explanation:

Step1: Determine protons in fluorine

Atomic number = 9, so protons = 9.

Step2: Check proton count in options

Only W and Y have 9 protons (X:10p, Z:9p but mass number mismatch).

Step3: Calculate electrons in neutral F

Neutral atom: electrons = protons = 9.

Step4: Identify ion (unequal e⁻/p⁺)

W has 10 electrons (≠9 protons), Y has 9 electrons (neutral). So W is the ion.

Answer:

A. W