When a light source moves away for an observer.
Answer:
126.5g
Explanation:
n=<u>m</u><u> </u>
M
where n is moles
m is mass of substance
M is molar mass
molar mass of sodium is 23g/mol
m=nM
m=5.5(23)
m=126.5
Answer:
Chromium
Explanation:
Cr has 24 atomic number and mass number 52