What is the primary hypothesis for the extinction of large mammals such as mammoths?

The primary hypothesis for extinction of mammoth was considered to be hunting by humans. A group of scientist thought that mammoth did not had genetic diversity until it was prooved as one large homogenous group. Hunting by humans were kept on the first place leaving the other factors like climatic change and disease behind. But the reality was something else, mammoth were divided into two groups, out of these two one group died before the appearance of the humans.

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.