At the molecular level, the heat comes from the agitation of the molecules and therefore their atoms. This increase in agitation causes the molecules to be less condensed between them and will separate after breaks in the intermlecular bonds. This distends the material, as we see when we heat a metal, or a transformation of the phase of the material, such as melting ice or boiling water.
A. Natural Selection. This is because the weeds that are not resistant to it die out before they can reproduce, but the resistant ones grow to maturity and then reproduce, passing down the resistance gene. Over time, the resistance gene would become a normal thing in weeds, while the non-resistant gene would not exist anyone, since the gene could not be passed on.
Though they are constantly changing, ecosystem are naturally BALANCED.
An ecosystem is said to be balanced, when the components of the ecosystem are in harmony. Two of the principal processes that usually throw ecosystems out of balance is pollution and hunting.
Answer: Methamphetamine
Explanation: Methamphetamine is a potent central nervous system(CNS) stimulant that is mainly used as a recreational drug and less commonly as a second line treatment for attention deficit hyperactivity disorder and obesity.
