What causes the inner core to remain a solid?

temperature

pressure

composition

the magnetic field created by the rotation of the liquid core outside it

Temperature

Explanation:

The inner core is solid because it is made of very dense, or heavy, materials - like iron and nickel. Even though it is very hot, these materials don't "melt" very easily, so they stay solid.

then that particular organisms become extinct.

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.