Sam is comparing the half-life of two isotopes of uranium. The half-life of Uranium-238 is 4.5 x 10^9 years. The half-life of Uranium-233 is 1.6 x 10^5 years. He computed how much greater the half-life of Uranium-238 is than that of Uranium-233, and his calculator displayed the number 2.81E4. What is the number in scientific notation.
a 4 x 10^2.81
b 2.81 + 10^4
c 2.81 x 10^-4
d 2.81 x 10^4
The number 2.81E4 in scientific notation is equivalent to option d: 2.81 x 10^4.
The number 2.81E4 in scientific notation is equivalent to option d) 2.81 x 10^4.
To determine the correct answer, let's compare the half-life of Uranium-238 with Uranium-233 and calculate the difference by dividing the half-life of Uranium-238 by the half-life of Uranium-233:
(4.5 x 10^9 years) / (1.6 x 10^5 years)
To divide the two numbers, subtract the exponents of 10 and divide the significant figures:
(4.5 / 1.6) x (10^9 / 10^5)
= 2.8125 x 10^(9-5)
= 2.8125 x 10^4
Therefore, the answer is:
d) 2.81 x 10^4