Understanding Atomic Mass and Isotopes

What determines the atomic number of an atom?

• The number of electrons

• The total mass of the atom

• The number of neutrons

• The number of protons

Why can't lithium have 3.9 neutrons?

• Neutrons are not part of the nucleus

• Lithium doesn't have neutrons

• Neutrons are always in pairs

• Neutrons can only be whole numbers

What is an isotope?

• Atoms with the same number of electrons but different protons

• Atoms with the same number of protons but different neutrons

• Atoms with the same mass number but different atomic numbers

• Atoms with the same number of neutrons but different electrons

Why is lithium's relative atomic mass closer to 7 than 6?

• Lithium-6 and Lithium-7 are equally abundant

• Lithium has no isotopes

• Lithium-7 is more abundant

• Lithium-6 is more abundant

What does the term 'relative atomic mass' refer to?

• The mass of an atom compared to hydrogen

• The mass of an atom compared to oxygen

• The mass of an atom compared to nitrogen

• The mass of an atom compared to carbon

What are radioisotopes?

• Isotopes with no protons

• Isotopes that emit radiation and decay

• Stable isotopes that do not decay

• Isotopes that are artificially created

What is measured by the half-life of a radioisotope?

• The time it takes for half of the isotope to decay

• The time it takes for the isotope to become stable

• The time it takes for the isotope to emit radiation

• The time it takes for the isotope to gain neutrons

Which element has the most stable isotopes?

• Tin

• Carbon

• Oxygen

• Lithium

What does it mean if an element is mono-isotopic?

• It has multiple stable isotopes

• It has no isotopes

• It has only one stable isotope

• It has only radioactive isotopes

Which elements have no stable isotopes?

• Lithium and Tin

• Technetium and Promethium

• Carbon and Oxygen

• Hydrogen and Helium