The question is incomplete. Complete question is attached below:
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Correct Answer:
Option A i.e FlammabilityReason:
Hydrochloric acid is a
strong acid. It has a high value of dissociation constant. Following equilibrium is established with HCl is dissolved in water
HCl + H2O ↔ Cl- + H3O+
Above, reaction is highly exothermic in nature. So care must be taken while preparing HCl solution of desired concentration.
HCl must be added in beaker containing water. Reversed, i.e. adding water in HCl, must never be done. This is because when acid is poured into water, it flows down the flask and mixes much efficiently and no boiling occurs. On other hand, <span> when water is added to acid, the very first drop of water will react with acid. The heat generated during this event might be high enough to boil the water instantly, which could spray acid out of the container.
The physical contact with concentration HCl will result in skin burn. As well, inhaling</span><span> HCl vapors can cause burns to body tissues, lung damage and even death in extreme cases. Also, since HCl is a strong acid, it would undergoes reaction almost spontaneously, which would inturn favour substitution reaction. However,
HCl is not a flammable gas. Hence, it is of no concern while performing substitution reaction. </span>
Answer:
b) a stickleback's aggressive behavior
Explanation:
Sticklebacks are small carnivores that live off of small animals and larvae. An adapted behaviour would be changes in their attitudes and behaviours as compared to the characteristics are given to them by the Creator.
For example lions nature is to hunt, spiders nature is to build nests whereas birds nature is to build nests. But being aggressive is not one of Sticklebacks natural instincts. This is something they have adapted with time due to external factors.
Question A is more testable through a scientific experiment because you have a specific thing you are trying to find out, "which gelatin takes longer to set".
Answer:
He
Explanation:
A molecule is the smallest physical unit of a substance that can exist independently, consisting of 2 or more atoms chemically combined
He is one atom of Helium