Question

for a science experiment, mr. duncan mixed 0.00055 pounds of sulfur and 0.00104 pounds of iron powder in a test tube before heating it. what is the total weight of the mixture in the test tube?

a. 6.54×10⁻⁴ pounds

b. 1.59×10⁻³ pounds

c. 1.59×10⁻⁴ pounds

d. 6.54×10³ pounds

Explanation:

Step1: Write numbers in standard form

$0.00055 = 5.5\times10^{-4}$ and $0.00104=1.04\times 10^{-3}=10.4\times 10^{-4}$

Step2: Add the two numbers

$(5.5\times 10^{-4})+(10.4\times 10^{-4})=(5.5 + 10.4)\times10^{-4}=15.9\times10^{-4}=1.59\times 10^{-3}$

Answer:

B. $1.59\times 10^{-3}$ pounds