Question

1.Какие суждения верны?1.Молекулы водыудерживаются друг околодруга коваными связями. 2.молекулыводыудерживаются друг околодруга водороднымиСВЯЗЯМИ. " З.ковалентные связи прочнеев 15—20 раз водородных. 4,Водородные связи прочнеев 15— : 20 раз ковалентных. 2.каково соотношениеионов натрия и калия по обестороны наружной клеточноймембраны? 1. Снаружи клетки всегда больше калияи меньше натрия, чемвнутри 2 Снаружи клетки всегда больше натрия именьше калия, чем внутри ,Натрия и калия снаружи клетки всегда больше, чемвнутри, 4Натрия и калия внутриклетки всегда больше, чем снаружи.

Answer 1

1.Верные суждения: 2,3.
2.Снаружи клетки всегда больше ионов натрия и меньше калия.

Answer 2

Molecules of water are held together by covalent bonds.

The statement that molecules of water are held together by covalent bonds is correct [[1]]. Covalent bonds are formed when two atoms share electrons, and in the case of water, the oxygen atom shares electrons with two hydrogen atoms to form water molecules.

Molecules of water are held together by hydrogen bonds.

The statement that molecules of water are held together by hydrogen bonds is also correct [[2]]. Hydrogen bonds are formed between the positively charged hydrogen atom of one water molecule and the negatively charged oxygen atom of another water molecule. These hydrogen bonds are weaker than covalent bonds but still play a crucial role in the unique properties of water.

The strength of covalent bonds compared to hydrogen bonds.

The statement that covalent bonds are stronger than hydrogen bonds is correct [[3]]. Covalent bonds are generally stronger than hydrogen bonds. Covalent bonds involve the sharing of electrons between atoms, while hydrogen bonds are formed due to the attraction between the positive and negative charges of different molecules.

The ratio of sodium and potassium ions on the outer cell membrane.

The statement that there is always more potassium and less sodium outside the cell is correct [[4]]. The concentration of potassium ions is higher inside the cell, while the concentration of sodium ions is higher outside the cell. This difference in ion concentration is maintained by ion pumps and channels in the cell membrane, which help regulate the movement of these ions.

In summary: - Molecules of water are held together by both covalent bonds and hydrogen bonds. - Covalent bonds are stronger than hydrogen bonds. - The concentration of potassium ions is higher inside the cell, while the concentration of sodium ions is higher outside the cell.

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