Calculating Atomic Mass and Isotopes

The video tutorial explains atomic structure, focusing on isotopes and atomic mass. It highlights the difference between mass number and atomic mass, using Carbon as an example. The concept of weighted average is introduced, contrasting it with regular average, using Boron isotopes to illustrate. The tutorial provides a step-by-step calculation of Boron's atomic mass, considering isotopic abundance. Another example with Magnesium demonstrates calculating atomic mass using its three isotopes. The video concludes with a call to action for viewers to engage on social media.

What particles are found in the nucleus of an atom?

• Protons and electrons

• Neutrons and electrons

• Protons and neutrons

• Electrons only

What is the mass number of an isotope?

• The number of protons

• The number of neutrons

• The number of electrons

• The sum of protons and neutrons

Why is the atomic mass of an element on the Periodic Table not a whole number?

• Because it includes the mass of electrons

• Because it is an average of the masses of all isotopes

• Because it is rounded to the nearest whole number

• Because it includes the mass of protons only

What is the difference between a weighted average and a regular average?

• A weighted average considers the relative abundance of each value

• A regular average considers the relative abundance of each value

• A weighted average is always higher than a regular average

• A regular average is always higher than a weighted average

Which isotope of Boron is more common in nature?

• Neither is common

• Boron-10

• Boron-11

• Both are equally common

What is the atomic mass of Boron-11?

• 10

• 11

• 10.5

• 10.8

What is the natural abundance of Boron-10 in the given sample?

• 20%

• 30%

• 10%

• 40%

How do you convert a percentage to a decimal for use in calculations?

• Move the decimal point two places to the left

• Divide by 10

• Multiply by 10

• Move the decimal point two places to the right

What is the average atomic mass of Magnesium?

• 24.31

• 25.31

• 23.31

• 26.31

Which isotope of Magnesium has the highest natural abundance?

• Magnesium-25

• Magnesium-26

• Magnesium-24

• All have equal abundance