What is odour. How it spreads into the air and sensible to human?

Question

What is odour. How it spreads into the air and sensible to human. Is it spreads as a particle, if so, then what about loss of energy and mass.

Answer 1

The concept you need to look up is vapor pressure. Molecules have a vapor pressure which is the pressure of the gas above the pure substane. Even many things that are mostly solid have some vapor pressure. When you cook food you heat the food up and the vapor pressure is higher at higher temperatures. When "smelly" molecules evaporate into the air, they do take energy with them, the heat of vaporization, thereby cooling whatever it is they evaporated from. Just like water evaporating from your skin. And, yes, they do take away mass from whatever they evaporate from. Our sense of smell is pretty sensitive and so only a little bit of evaporation has to take place before we smell the substance.

For instance, when you put on cologne, the alchohol evaporates immediately but the fragrance evaporates slowly over the course of the day, only a tiny bit at a time but its enough for people to smell.

If you feel like doing an experiment, you can take something that evaporates alot, like bread, weigh it on a food scale, let it sit open on your kitchen counter until its all dried and crusty and then weigh it again. It should have lower weight beause of the weight of water that evaporated.

Answer 2

An odor or odour (see spelling differences) is a chemical dissolved in air, generally at a very low concentration, which we perceive by the sense of olfaction. Odors are also called smells, which can refer to both pleasant and unpleasant odors. In contrast, stench, reek, and stink are used specifically to describe an unpleasant odor. The terms fragrance, scent, or aroma are used primarily by the food and cosmetic industry to describe a pleasant odor, and is sometimes used to refer to perfumes.

Odor is a sensation caused by odorant molecules dissolved in air. The widest range of odors consist of organic compounds although some inorganic substances, such as hydrogen sulfide and ammonia, are also odorants. The perception of an odor effect is a two step process. First, there is the physiological part; the sense of the stimulus by receptors in the nose. After that the psychological part follows. The stimuli are processed by the region of the human brain which is responsible for smelling. Because of this an objective and analytical measure of odor is impossible. While odor feelings are very personal perceptions, individual reactions are related to gender, age, state of health and private affectations. Common odors that people are used to, such as their own body odor, are less noticeable to individuals than external or uncommon odors.

For most people, the process of smelling gives little information concerning the ingredients of a substance. It only offers information related to the emotional impact. However, experienced people, such as flavorists and perfumers can pick out individual chemicals in complex mixes through smell alone..

Answer 3

odour is the fragrance or the smell which you are able to sense it . for example --- when a perfume is sprayed in the air , the odour quickly spreads in the air due to a phenomenon called diffusion . Diffusion is the movement of molecules or ions of a substance in it's solid , liquid or gaseous state from a region of their higher concentration to a region of their higher concentration till a uniform concentration is obtained . When it reaches our nose , our nose is able to judje the diffence and hence we can sense the fragrance

Answer 4

Smell is a means for the body to sense molecules in the environment. When you smell an object, it means that a molecule from that object has traveled through the air and into your nose, where the body's sensors detect it. Your brain interprets this detection as what you know to be the object's "smell".

Answer 5

Odor is simply small amounts of gaseous molecules dispersed into the air. Our nose has receptor sites that are sensitive to some of these molecules, and so we smell something.

Same effect as when our tongue tastes something.

Answer 6

eweee. I just run to a stall and hold my nose... Do my duty, then wash up and leave really fast. If it is really bad, then I pretend to look at myself in the mirror, if someone is watch me when I enter the r/r. Then I politely make a quick exit.