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.
6.54 × 103 pounds
C.
1.59 × 10-3 pounds
D.
1.59 × 10-4 pounds

Answer 1

To find the total weight of the mixture in the test tube, you need to add the weight of sulfur and the weight of iron powder together.

Weight of sulfur: 0.00055 pounds
Weight of iron powder: 0.00104 pounds

First, it's easier to add these values if they are expressed in the same format. We convert them to scientific notation:

- 0.00055 pounds = \(5.5 \times 10^{-4}\) pounds
- 0.00104 pounds = \(1.04 \times 10^{-3}\) pounds

To add these, we can convert \(1.04 \times 10^{-3}\) to the same exponent as \(5.5 \times 10^{-4}\):

\(1.04 \times 10^{-3} = 10.4 \times 10^{-4}\)

Now we can add:

\[
5.5 \times 10^{-4} + 10.4 \times 10^{-4} = (5.5 + 10.4) \times 10^{-4} = 15.9 \times 10^{-4}
\]

Now, we can convert \(15.9 \times 10^{-4}\) back to standard scientific notation:

\[
15.9 \times 10^{-4} = 1.59 \times 10^{-3} \text{ pounds}
\]

Thus, the total weight of the mixture in the test tube is:

**C. \(1.59 \times 10^{-3}\) pounds**