Select all the statements that apply to diffusion. A.
It requires energy to move molecules.

B.
It doesn’t take energy to move molecules in and out.

C.
Molecules move from high to low concentration.

D.
Molecules move from low to high concentration.

B and C

Explanation:

Diffusion happens across the concentration gradient, the gradient goes from high to low concentration. This is natural and requires no energy. The only type of diffusion that requires energy is called active transport, this is when molecules move from low to high.

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.