Every chemical element goes through natural exponential decay, which means that over time its atoms fall apart. The speed of each element's decay is described by its half-life, which is the amount of time it takes for the number of radioactive atoms of this element to be reduced by half.The half-life of the isotope dubnium- 263 is 29 seconds. A sample of dubnium−263 was first measured to have 1024 atoms. After t seconds, there were only 32 atoms of this isotope remaining.Write an equation in terms of t that models the situation.
Q. Every chemical element goes through natural exponential decay, which means that over time its atoms fall apart. The speed of each element's decay is described by its half-life, which is the amount of time it takes for the number of radioactive atoms of this element to be reduced by half.The half-life of the isotope dubnium- 263 is 29 seconds. A sample of dubnium−263 was first measured to have 1024 atoms. After t seconds, there were only 32 atoms of this isotope remaining.Write an equation in terms of t that models the situation.
Exponential Decay Formula: The general formula for exponential decay is N(t)=N0×(21)Tt, where N(t) is the number of atoms at time t, N0 is the initial number of atoms, (21) is the decay factor, and T is the half-life of the substance.
Substitute Values: Given that the half-life T of dubnium−263 is 29 seconds, we can substitute this value into the formula. We also know that the initial number of atoms N0 is 1024, and the remaining number of atoms N(t) after time t is 32.
Isolate Exponential Term: Substitute the given values into the decay formula: 32=1024×(1/2)(t/29).
Simplify Equation: To find the equation in terms of t, we need to solve for t. First, divide both sides of the equation by 1024 to isolate the exponential term: 102432=(21)29t.
Recognize Exponential Form: Simplify the left side of the equation: 321=(21)29t.
Set Exponents Equal: Recognize that 321 is 2−5 since 25=32. Therefore, we can rewrite the equation as 2−5=(21)29t.
Solve for t: Since 21 is the same as 2−1, we can rewrite the equation as 2−5=2−29t.
Calculate Final Value: By the property of exponents, if the bases are the same, then the exponents must be equal. Therefore, we can set the exponents equal to each other: −5=−29t.
Calculate Final Value: By the property of exponents, if the bases are the same, then the exponents must be equal. Therefore, we can set the exponents equal to each other: −5=−29t.Multiply both sides of the equation by −29 to solve for t: −5×−29=t.
Calculate Final Value: By the property of exponents, if the bases are the same, then the exponents must be equal. Therefore, we can set the exponents equal to each other: −5=−29t. Multiply both sides of the equation by −29 to solve for t: −5×−29=t. Calculate the value of t: t=145.
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