Chemical hoods used in our laboratories protect workers using volatile hazardous materials. Which of the following statements is true? A. A worker should feel a steady draft entering the face of the hood.
B. A worker should not feel air moving around the chemical hood.
C. A worker should feel a steady draft emerging from the face of the hood.

B. A worker should not feel air moving around the chemical hood.

Explanation:

Hello!

In this case, since chemical hoods are used to remove the hazardous vapors given off by volatile chemicals, the idea is that the workers do not get in contact, in anyway, with those vapors as they can affect their health and safety at the laboratories.

It means that options A and C are ruled out  because they describe an scenario in which the worker is in contact with the vapors and also because the vapors are removed via a fan system that withdraws the vapors.

Therefore the correct option is B. A worker should not feel air moving around the chemical hood.

Best regards!

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

i believe it is c.) 1575 j.