Answer:
5ppm
Explanation:
there are 1 million (1,000,000) µg (micrograms or mcg) per g (gram) ("micro" means millionth). So, 4. 1 part per million (ppm) for a 1g sample is 1 µg or .
I know you said no links, but this is a converter that explained it much better than I know how to
http://www.endmemo.com/sconvert/ppmug_g.php#:~:text=%C2%BB%20Microgram%2Fgram%20Conversions%3A&text=ug%2Fg%E2%86%94ppm%201%20ug%2Fg%20%3D%201%20ppm
heres a screenshot of the site (since i understand links are awful)
