Understanding Atomic Structure Using the Periodic Table

What does the atomic number of an element represent?

• The total number of electrons and neutrons

• The number of neutrons in the nucleus

• The total number of protons and neutrons

• The number of protons in the nucleus

Why must the number of protons equal the number of electrons in an atom?

• To maintain electrical neutrality

• To ensure the atom is positively charged

• To increase the atomic number

• To make the atom heavier

How do you calculate the number of neutrons in an atom?

• Divide the mass number by the atomic number

• Multiply the atomic number by the mass number

• Add the atomic number to the mass number

• Subtract the atomic number from the mass number

In the example of magnesium, what is the number of neutrons?

• 6

• 18

• 12

• 24

For boron, if the atomic number is 5 and the mass number is 11, how many neutrons are present?

• 11

• 6

• 5

• 16