(1.7 x 10^-4)(5 x 10^-5)
A)8.5 10-9
B)8.5-1020
C)6.7.10-9
D)6.7-1020
The answer is C) 6.7 x 10^-9.
To multiply numbers in scientific notation, you multiply the coefficients (1.7 x 5 = 8.5) and add the exponents (10^-4 + 10^-5 = 10^-9), giving you 8.5 x 10^-9, which is equivalent to 6.7 x 10^-9 when rounded to one significant figure.
To multiply two numbers expressed in scientific notation, we can multiply their significant figures and then add the exponents.
Given:
(1.7 × 10^-4) × (5 × 10^-5)
1. Multiply the significant figures: 1.7 × 5 = 8.5
2. Add the exponents: 10^-4 + 10^-5 = 10^-9
So the answer is 8.5 × 10^-9.
Therefore, the correct option is A) 8.5 × 10^-9.