Answer:
Endoplasmic reticulum.
Explanation:
Second messengers are known as intracellular signaling molecules released from the cell in response to exposure to extracellular signaling molecules. Second messenger activate physiological changes at a cellular level, for example proliferation, migration, differentiation, survival, and apoptosis.
Calcium ions are hydrophilic, water-soluble molecules. They are present in intracellular component know as endoplasmic reticulum and quickly released when needed. They are necessary for many important functions including fertilization, muscle contractions, and neurotransmitter release.
Ice and water because it can be froze and gets really cold
equalize the coefficients:
Al(NO3)3+3NaCl=3NaNO3+AlCl3
according to the equation 1 mol Al(NO3)3 reacted with 3 moles NaCl. hence, 4 moles Al(NO3)3 should react with 12 moles NaCl, and 9 moles reacted NaCl. So NaCl is limiting, we decide further on this reagent.
\frac{9}{3}=\frac{x}{3}
3
9
=
3
x
x=9
9 moles NaNO3
B rusting iron because whatever is making it rust is reacting with the iron to cause it to rust.