Strontium 90, a Radioactive Isotope of Strontium, Is Present in the Fallout

question 72

Multiple Choice

Strontium 90, a radioactive isotope of strontium, is present in the fallout resulting from nuclear explosions. It is especially hazardous to animal life, including humans, because, upon ingestion of contaminated food, it is absorbed into the bone structure. Its half-life is 27 years. If the amount of strontium 90 in a certain area is found to be four times the "safe" level, find how much time must elapse before an "acceptable level" is reached.

• A) 30.3 year(s) must elapse before an "acceptable level" is reached.
• B) 54 year(s) must elapse before an "acceptable level" is reached.
• C) 57 year(s) must elapse before an "acceptable level" is reached.
• D) 39 year(s) must elapse before an "acceptable level" is reached.

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Definitions:

Drawing Account

An account used to record withdrawals made by a business owner or partner from the company for personal use.

Balance Sheet Debit

An entry on the left side of a balance sheet, typically indicating an increase in assets or a decrease in liabilities or equity.

Net Income

Profits after subtracting all costs, including operating expenses, interest, and taxes, from total revenue, indicating the final earning outcome of a business.

Adjusted Trial Balance

A financial report that lists all the account titles and balances of a company after adjusting entries are made, used for the preparation of financial statements.