Most animals obtain their nutrients by the consumption of other organisms. At the cellular level, the biological molecules necessary for animal function are amino acids, lipid molecules, nucleotides, and simple sugars. However, the food consumed consists of protein, fat, and complex carbohydrates.
You should take note that the question is about stability. A compound is stable if it does not easily react with other elements. Hence, its reactivity must be low. As you move down the group, reactivity decreases. So, the halide at the very bottom is the least reactive. It would then be logical that the most stable conjugate base is I⁻ and the least stable conjugate base is the most reactive which is F⁻.
you calculate all the letters together and it would be Zn2
As glaciers melted at the end of the last Ice Age worldwide sea level increased immensely and river plains were flooded. Glaciers are floating bodies of ice. Ice is frozen water. When glaciers started melting water that had been frozen for decades or centuries was released back into the ocean. That lead to an increase in sea level. This also led to river plains being drowned/flooded. Therefore, the answer is 1 and 2.