Radioactive Isotopes and Dating Methods

The video tutorial explains absolute dating, focusing on radioactive decay to determine the age of rocks and fossils. It covers basic chemistry concepts, such as atoms and isotopes, and details the process of radioactive decay. The tutorial provides an example using carbon-14 to date fossils and discusses other isotopes like potassium-40, uranium-238, and rubidium-87 used for dating different materials.

What is the primary purpose of absolute dating?

• To identify the chemical composition of rocks

• To determine the relative age of rocks

• To determine the actual age of rocks and fossils

• To find the exact location of fossils

Which subatomic particle has a positive charge?

• Neutron

• Proton

• Electron

• Photon

What distinguishes isotopes of the same element?

• Different number of protons

• Different number of electrons

• Different atomic numbers

• Different number of neutrons

What is the term for the time it takes for half of a radioactive isotope to decay?

• Isotope duration

• Half-life

• Radioactive interval

• Decay period

Which isotope is commonly used to date organic materials up to 50,000 years old?

• Uranium-238

• Potassium-40

• Carbon-14

• Rubidium-87

After one half-life, what happens to the amount of a radioactive isotope?

• It doubles

• It remains the same

• It completely decays

• It is reduced by half

Which isotope is used to date very old rocks and fossils?

• Carbon-14

• Potassium-40

• Uranium-238

• Rubidium-87

What is the half-life of uranium-238 used for dating the age of the Earth?

• 5,700 years

• 4.6 billion years

• 49 billion years

• 1.3 billion years

Why is rubidium-87 not used for dating rocks on Earth?

• It is unstable

• It is not radioactive

• Its half-life is too short

• Its half-life is too long

What does potassium-40 decay into?

• Strontium-87

• Nitrogen-14

• Argon-40 and Cadmium-40

• Lead-206