The most abundant of all of the isotopes of an element will be the one who's mass the mass of element is closest to. In this case, the mass of atomic carbon is closest to the mass of carbon-12.
Thus, Carbon-12 is the most abundant isotope.
The biological compounds that are nonpolar and insoluble in water are lipids. It is a group of molecules that are naturally occurring which includes sterols, waxes, fats, fat-soluble vitamins and the like. These molecules are nonpolar molecules so basically the cannot be dissolved in a polar solvent like water.
Yes, anything with carbonate, hydrogen carbonate (bicarbonate) at the end is a carbonate.
Examples:NaHCO3 (Sodium hydrogen carbonate or Sodium bicarbonate)Na2CO3 (Sodium carbonate)
2NaBr + Ca(OH)2 ➡️ CaBr2 + 2NaOH