Day 4 - Stability and Half-Life

Day 4 - Stability and Half-Life

Multiple Choice

What determines the stability of an atomic nucleus?

• the ratio of neutrons to protons

• the ratio of neutrons to electrons

• the ratio of protons to electrons

• the ratio of energy levels to mass

Multiple Choice

What group of elements are always unstable?

• ions

• isotopes

• atoms with a mass over 83

• atoms with an atomic number over 83

Multiple Choice

What is Half-life?

• The amount of time it takes for some of the nuclei in a sample of the isotope to decay

• The amount of time it takes for half the electrons in a sample of the isotope to decay

• The amount of time it takes for half the nuclei in a sample of the isotope to decay

• the amount of time it takes to double the nuclei in a sample of the isotope to decay

Fill in the Blank

How long are 3 half-lives?

Fill in the Blank

How many grams of isotope remains at the end of 3 half-lives?

Fill in the Blank

How many half-lives did the sample go through at the end of 10.4 hours?

Fill in the Blank

What is the mass of manganese-56 in a 1.0mg sample of the isotope at the end of 10.4 hours?