Real-Life Applications of Half-Life: Decay and Growth Quiz

A radioactive substance has a half-life of 5 years. If you start with 80 grams, how much will remain after 15 years?

• 20 grams

• 5 grams

• 40 grams

• 10 grams

A certain medication has a half-life of 3 hours. If a patient takes a dose of 120 mg, how much of the medication will be left in their system after 9 hours?

• 45 mg

• 30 mg

• 60 mg

• 15 mg

A scientist discovers a new element that decays exponentially with a half-life of 10 days. If the initial amount is 200 mg, how much will be left after 30 days?

• 100 mg

• 50 mg

• 10 mg

• 25 mg

A tree species is known to decay at a rate where its half-life is 12 years. If a forest starts with 500 trees, how many trees will remain after 36 years?

• 62

• 200

• 250

• 100

A certain isotope has a half-life of 2 years. If you have 64 mg of this isotope, how much will be left after 8 years?

• 4 mg

• 8 mg

• 16 mg

• 32 mg

A car depreciates in value at a rate that can be modeled by a half-life of 4 years. If the car's initial value is $20,000, what will its value be after 12 years?

• $10,000

• $15,000

• $5,000

• $2,500

A certain bacteria population doubles every 3 hours. If the initial population is 500, how many will there be after 12 hours?

• 2000

• 4000

• 10000

• 8000

A chemical compound has a half-life of 6 months. If you start with 1 liter of the compound, how much will remain after 1.5 years?

• 0.5 liters

• 0.75 liters

• 0.25 liters

• 0.125 liters

A certain type of fish population decreases exponentially with a half-life of 5 years. If there are initially 1,000 fish, how many will be left after 15 years?

• 250

• 500

• 750

• 125

A new type of battery has a half-life of 2 years. If you start with 100% charge, what percentage of the battery will remain after 6 years?

• 75%

• 25%

• 12.5%

• 50%