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What belongs in each mystery box?

Every mystery box holds the same value. Make the two sides balance.

5 × ? + 666Equal values make a level balance.

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ScienceAges 16-18Physics (O Level): Nuclear physics
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Radioactive half-life decay

A radioactive sample has an initial mass of 18 g and a half-life of 2 days. How many grams of the isotope remain undecayed after 2 days?

Calculate the remaining activity (Bq) of a radioactive sample after a whole number of half-lives.

N₀ = 18 g (t₁/₂ = 2 d) · t = 2 days
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