Atomic Mass Numbers?

The video tutorial explains why atomic masses are not whole numbers, focusing on isotopes and their relative abundance. It uses chlorine and bromine as examples to demonstrate how to calculate the relative atomic mass, which is a weighted mean of the isotopes' masses. The tutorial concludes by emphasizing the importance of isotopes in determining atomic masses.

Why are atomic masses not always whole numbers?

• Due to errors in measurement.

• Due to the presence of electrons.

• Because atoms are not perfectly spherical.

• Because of the presence of isotopes with different neutron numbers.

What are the two most common isotopes of chlorine?

• Chlorine 36 and Chlorine 38

• Chlorine 37 and Chlorine 39

• Chlorine 35 and Chlorine 37

• Chlorine 34 and Chlorine 36

How is the relative atomic mass of an element calculated?

• By adding the masses of protons and neutrons.

• By considering the weighted mean of isotopes based on their abundance.

• By using the mass of the most common isotope.

• By averaging the masses of all isotopes.

What is the relative atomic mass of bromine if it contains 50% bromine-79 and 50% bromine-81?

• 82

• 79

• 80

• 81

What does the term 'weighted' mean in the context of atomic mass?

• It is the average mass of all isotopes.

• It refers to the mass of the heaviest isotope.

• It is the mass of the isotope with the most protons.

• It considers the relative abundance of each isotope.