Answer:
The chronic daily intake during the period of exposure is most nearly 0.012 mg/kg day.
Explanation:
Number of hours worker exposed to xylene = 
The concentration of xylene in the workplace =
The worker is inhaling air at a rate of
.
Amount xylene inhaled by worker in an hour :
= 
Amount xylene inhaled by worker in 320 hours:

1 μg = 0.001 mg
Amount xylene inhaled by worker in 320 hours = 11.520 mg
1 day = 24 hours
Amount xylene inhaled by worker in 1 day:

Assuming 70 kg body mass, the chronic daily intake of xylene :

The chronic daily intake during the period of exposure is most nearly 0.012 mg/kg day.
Atoms have no electric charge because the protons and electrons "cancel out" each others charges. Neutrons have no charge. What is the atomic number of an element? The atomic number is the number of protons in the atom's nucleus.
Hope this helps have a great day :)
Answer:
lithium=atomic no.=3
Explanation:
-1 charge on lithium means one electron has added to it .Thus,
Li-1=no. of electrons=3+1=4
The answer is A) KF. The rest are covalent.