Question

how many grams are in 21.54 milligrams? *
2154 grams
0.2154 grams
215.4 grams
0.02154 grams
2.154 grams
how can we write 50 to exactly five significant figures? *
50.000
neither of these is correct
5.0000x10²
both of these are correct

Explanation:

Step1: Recall conversion factor

1 gram = 1000 milligrams, so 1 milligram=$\frac{1}{1000}$ grams = 0.001 grams.

Step2: Convert 21.54 milligrams to grams

21.54 milligrams = 21.54×0.001 grams = 0.02154 grams.

Step3: Understand significant - figures for 50

To write 50 with five significant figures, we can write it as 50.000 (in decimal form) or 5.0000×10¹ (in scientific - notation).

Answer:

1. D. 0.02154 grams
2. A. 50.000