I believe it is because the glass has a smaller coefficient of linear expansion than the water. The glass undergoes thermal expansion and thus when it heats up, it expands and when it cools down it contracts. The inside and the outside of the glass does not reach an equilibrium temperature very quickly since the glass has a low thermal conductivity. The surface of the glass rapidly contracts while the inner surface is expanding which causes the glass to crack.
There must be a change in the chemical composition of the substance and the change is highly irreversible
Answer:
Explanation:
Smaller cells, with a larger surface area to volume ratio, are more efficient for diffusing materials in and out because, as a cell grows, the volume grows faster than the surface area.
-sorry if this doesn't help-
Answer:
Hormones act as first messenger but not as second messengers.
Explanation:
Second messenger act as signaling molecule which are secreted in response to various biological signals generated by first messenger such as hormones,neurotransmitters etc.Second messengers include various bioactive molecules such as cyclic AMP(cAMP),cyclic GMP(cGMP),inositol triphosphate(IP3),diacylglycerol(DAG),calcium ions(Ca2+) etc.
Hormones are extracellular signaling molecules whereas second messengers are intracellular signaling molecules.