Isotopes and Atomic Structure

The video tutorial explains how to determine the number of protons, neutrons, and electrons in magnesium isotopes. Magnesium has three stable isotopes: magnesium-24, magnesium-25, and magnesium-26. The atomic number of magnesium is 12, which equals the number of protons and electrons in a neutral atom. The video discusses how different isotopes have varying numbers of neutrons, affecting their mass numbers. It also covers the concept of ions and how to use nuclear notation to represent isotopes. The average atomic mass is influenced by the abundance of each isotope.

What is the atomic number of magnesium?

• 13

• 11

• 12

• 10

In a neutral magnesium atom, how do the number of protons compare to the number of electrons?

• Protons are more

• They are equal

• Cannot be determined

• Electrons are more

What changes between different isotopes of the same element?

• Atomic number

• Number of neutrons

• Number of electrons

• Number of protons

What is the mass number of the most abundant magnesium isotope?

• 25

• 24

• 23

• 22

How many neutrons are present in magnesium-25?

• 12

• 13

• 11

• 14

What percentage of magnesium atoms have a mass number of 25?

• 20%

• 5%

• 10%

• 15%

Which isotope of magnesium has 14 neutrons?

• Magnesium-24

• Magnesium-25

• Magnesium-26

• Magnesium-27

What is the purpose of nuclear notation?

• To show the average atomic mass

• To represent specific isotopes

• To calculate atomic number

• To determine electron configuration

In nuclear notation, where is the atomic number placed?

• Bottom right

• Top right

• Top left

• Bottom left

Can the number of isotopes for an element be determined just by looking at the periodic table?

• No, never

• Yes, always

• Yes, for some elements

• No, except for hydrogen