Question

Question
Sam is comparing the half-life of two isotopes of uranium. The half-life of Uranium-238 is 4.5×109
years. The half-life of Uranium-233 is 1.6×105
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 this number in scientific notation?(1 point)
Responses

4×102.81

4 times 10 superscript 2.81 baseline

2.81+104

2.81 plus 10 superscript 4 baseline

2.81×104

2.81 times 10 superscript 4 baseline

2.81×10−4

Answer 1

2.81 × 10^4

Explanation: (4.5×10^9)/(1.6×10^5) = (4.5/1.6)×10^(9−5) ≈ 2.8125×10^4, which is 2.81E4 in scientific notation.