Atomic Masses and Composition of Nucleus

The video tutorial explains how physicists measure atomic mass using atomic mass units (u), defined as 1/12 of a carbon-12 atom's mass. It discusses isotopes, which are atoms with the same chemical properties but different masses, using chlorine and hydrogen as examples. The video also covers the discovery of neutrons by James Chadwick, highlighting their role in atomic nuclei alongside protons. It explains atomic structure, including protons, electrons, and neutrons, and introduces concepts like atomic number, mass number, isotopes, isobars, and isotones.

What unit do physicists use to measure the mass of atoms?

• Grams

• Kilograms

• Atomic Mass Unit

• Milligrams

How is the average atomic mass of chlorine calculated?

• By using the mass of a single chlorine atom

• By considering the relative abundance of each isotope

• By averaging the masses of all isotopes equally

• By taking the mass of the heavier isotope only

Which scientist is credited with the discovery of the neutron?

• Albert Einstein

• James Chadwick

• Ernest Rutherford

• Niels Bohr

What happens to neutrons once they are outside the nucleus?

• They transform into a photon

• They remain stable indefinitely

• They decay into a proton, electron, and antineutrino

• They become positively charged

What is the atomic number of an element?

• The number of neutrons in the nucleus

• The number of electrons in the outer shell

• The number of protons in the nucleus

• The total number of protons and neutrons

What are isobars?

• Nuclides with identical electronic structures

• Nuclides with the same number of neutrons but different atomic numbers

• Nuclides with the same mass number but different atomic numbers

• Nuclides with the same atomic number but different mass numbers

Which of the following is an example of isotones?

• 1H1 and 1H2

• 80Hg198 and 79Au197

• 1H3 and 2He3

• 79Au197 and 79Au198