Activated charcoal is used in gas
masks. what physical property is
related to this use?

Answer:

physical property is  related to the use of Activated charcoal  in gas  masks is  Physical adsorption

Explanation:

Respirators in the gas masks has a 2-stage inhalation protection process . In the first step, particle filter is used that behaves like a physical barrier that removes bacteria from air which is inhaled. When the bacteria is inhaled, it gets entangled in the filter fibres preventing it from being inhaled into the lungs.

In the next stage , activated charcoal is used .This layer with highly porous charcoal attracts and binds to toxins. Through adsorption process, a solid or a liquid can trap particles on its surface. Toxins that pass through the charcoal become bonded to its surface, preventing inhalation of the toxins.  

answer: a chemical reaction

explanation:

im not wrong

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.