Aperson sneezes due to smelling strong perfume. this is an example of what kind of stimuli?

a. chemicals

b. light

c. touch

d. sound

A. Chemical stimuli

Explanation:

What is stimuli?

Basically stimuli is anything that causes a response or triggers a reaction

Chemical stimuli,chemicals such as deodorants, are received by cellular receptors that are often coupled to ion channels responsible for chemotransduction.

Chemical stimuli can be interpreted by a chemoreceptor that interprets chemical stimuli, such as an object's taste or smell.

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.