Decoding Average Atomic Mass and Its Decimal Representation

The video tutorial explores the periodic table, focusing on atomic numbers and mass numbers. It explains the concept of weighted averages using exam scores as an example and relates it to calculating average atomic mass for elements with isotopes. The tutorial highlights common mistakes in these calculations and emphasizes the importance of considering relative abundances of isotopes.

What defines the element in the periodic table?

• Number of neutrons

• Atomic mass

• Number of electrons

• Number of protons

Why can't we have decimal places in the mass number?

• Because it represents the number of nucleons

• Because it represents the number of electrons

• Because it represents the number of neutrons

• Because it represents the number of protons

In the given scenario, what percentage of the final mark is assigned to coursework?

• 100%

• 70%

• 50%

• 30%

If a student scores 78% in coursework and 60% in the final exam, what is their overall mark?

• 70.2%

• 74.5%

• 72.6%

• 68.4%

What is an isotope?

• An element with a different atomic number

• An element with a different number of neutrons

• An element with a different number of electrons

• An element with a different number of protons

Which isotope of magnesium is the most common?

• Magnesium-24

• Magnesium-26

• Magnesium-27

• Magnesium-25

How do we calculate the average atomic mass of an element?

• By averaging the atomic numbers of all isotopes

• By adding the masses of all isotopes and dividing by the number of isotopes

• By using a weighted average of the masses of all isotopes

• By taking the mass of the most common isotope

What is the average atomic mass of magnesium?

• 24.29

• 25.00

• 26.00

• 24.00

What common mistake do students make when calculating average atomic mass?

• Ignoring the relative abundances of isotopes

• Adding the masses of isotopes incorrectly

• Using the atomic number instead of the mass number

• Using the wrong units

Why do we have decimal places on the periodic table?

• Because of the atomic number

• Because of the number of electrons

• Because of the relative atomic mass

• Because of the number of protons