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.
i believe the answer is...
Atoms of isotopes of an element have different numbers of protons.
Metalloids are all solid at room temperature<span>. Some metalloids, such as silicon and germanium, can act as </span>electrical<span> conductors under the right conditions, thus they are called semiconductors. Silicon, for example, appears lustrous but is not malleable or </span>ductile<span> (it is brittle - a characteristic of some nonmetals).
If this helped, please give me brainliest :)</span>