The Periodic Table: Mass Number and Atomic Mass

The video tutorial explains the concept of atomic mass, focusing on subatomic particles like protons and neutrons. It introduces the atomic mass unit (AMU) as a measure for these particles. The tutorial details how to calculate the mass number by adding protons and neutrons, using carbon as an example. It also discusses isotopes, which are atoms of the same element with different neutron counts, affecting the atomic mass. The atomic mass is a weighted average of all isotopes, often resulting in a decimal value.

What unit is used to measure the mass of subatomic particles?

• Pound

• Atomic Mass Unit

• Gram

• Kilogram

How is the mass number of an atom determined?

• By adding the number of protons and neutrons

• By calculating the electron cloud density

• By counting the electrons

• By measuring the atomic radius

What is the mass number of a carbon atom with six protons and six neutrons?

• 24 AMU

• 6 AMU

• 12 AMU

• 18 AMU

What are isotopes?

• Atoms with the same number of protons but different numbers of neutrons

• Atoms with the same number of neutrons but different numbers of protons

• Atoms with the same number of protons and neutrons

• Atoms with the same number of electrons but different numbers of protons

Why is the atomic mass of an element not usually a whole number?

• Because it includes the mass of electrons

• Because it is a weighted average of all isotopes

• Because it only considers the most common isotope

• Because it is rounded to the nearest whole number