Understanding Isotopes and the Periodic Table

What is the atomic number of an element?

• The total mass of an atom

• The number of protons in an atom

• The number of electrons in an atom

• The number of neutrons in an atom

Which of the following best describes an isotope?

• Atoms with the same mass number

• Atoms with the same number of protons and neutrons

• Atoms with different numbers of protons

• Atoms of the same element with different numbers of neutrons

Why does sodium have the symbol 'Na'?

• It is derived from its Latin name

• It is a random assignment

• It was discovered in America

• It is derived from its German name

What is the atomic number of magnesium?

• 11

• 12

• 13

• 14

How many naturally occurring isotopes does magnesium have?

• Three

• Five

• Two

• Four

Which isotope of magnesium has 13 neutrons?

• Magnesium-24

• Magnesium-25

• Magnesium-26

• Magnesium-27

Where is the atomic number placed in an isotope symbol?

• Lower right corner

• Upper right corner

• Lower left corner

• Upper left corner

What is the mass number of an isotope with 12 protons and 14 neutrons?

• 24

• 25

• 26

• 27

How can isotopes be designated using their full names?

• By writing the element name followed by the number of electrons

• By writing the element name followed by the mass number

• By writing the element name followed by the number of neutrons

• By writing the element name followed by the atomic number

What is the key difference between isotopes of the same element?

• Different atomic numbers

• Different numbers of protons

• Different numbers of electrons

• Different numbers of neutrons