Question

25
mn
54.938
atomic # =
atomic mass =

of protons =

of neutrons =

of electrons =

9
fluorine
18.998
atomic # =
atomic mass =

of protons =

of neutrons =

of electrons =

Explanation:

For Manganese (Mn):

Step1: Atomic Number

The atomic number (Atomic #) is the top number in the element box, so for Mn, Atomic # = 25.

Step2: Atomic Mass

The atomic mass is the bottom number, so Atomic Mass = 54.938.

Step3: Number of Protons

Number of protons equals atomic number, so # of Protons = 25.

Step4: Number of Neutrons

Neutrons = Atomic Mass (rounded) - Atomic Number. Rounded atomic mass of Mn is 55, so 55 - 25 = 30. Thus, # of Neutrons = 30.

Step5: Number of Electrons

In a neutral atom, electrons = protons, so # of Electrons = 25.

For Fluorine (F):

Step1: Atomic Number

Atomic # is the top number, so Atomic # = 9.

Step2: Atomic Mass

Atomic Mass is the bottom number, so Atomic Mass = 18.998.

Step3: Number of Protons

Protons = atomic number, so # of Protons = 9.

Step4: Number of Neutrons

Neutrons = Atomic Mass (rounded) - Atomic Number. Rounded atomic mass is 19, so 19 - 9 = 10. Thus, # of Neutrons = 10.

Step5: Number of Electrons

Electrons = protons (neutral atom), so # of Electrons = 9.

Answer:

Manganese (Mn):

• Atomic # = 25
• Atomic Mass = 54.938
• # of Protons = 25
• # of Neutrons = 30
• # of Electrons = 25

Fluorine (F):

• Atomic # = 9
• Atomic Mass = 18.998
• # of Protons = 9
• # of Neutrons = 10
• # of Electrons = 9