Any buffer exists in this equilibrium
HA <=>

In a buffer, there is a large reservoir of both the undissociated acid (HA) and its conjugate base (

)
When a strong acid is added, it reacts with the large reservoir of the conjugate base (

) forming a salt and water. Since this large reservoir of the conjugate base is used, the ph does not alter drastically, but instead resist the pH change.
Answer: D. Slow down the chain reaction by absorbing free neutrons
Explanation: just got it right on the quiz A P E X
The answer is C. Nicotine is the substance found in tobacco smoke that stimulates the brain.
Answer:
Basically, solubility increases with temperature. It is the case for most of the solvents. The situation is though different for gases. With increase of the temperature they became less soluble in each other and in water, but more soluble in organic solvents.
Answer: The elements with properties intermediate between those of metals and nonmetals are called semimetals (or metalloids).