J.R. S. answered 09/17/19
Ph.D. University Professor with 10+ years Tutoring Experience
To do these types of calculations, you MUST know the conversion factor. Just as you know that 1 dozen =12, or one pair = 2, in this case you need to know the following:
kg = 1000 g = 103 g
mg = 10-3 g
ug = 10-6 g
Now, taking what is given and doing some conversions:
260.0 ug x 1 mg/103 ug = 0.2600 mg x 1 g/103 mg = 2.600x10-4 g x 1 kg/103 g = 2.600x10-7 kg
Alternatively, form the above conversion factors, you can see that 1 kg = 109 ug. Using this conversion, we have... 260.0 ug x 1 kg/109 ug = 260.0x10-9 kg = 2.600x10-7 kg