I think it's D) because I found this fact.
Loss of significant amounts of body fat will compromise an individual's ability to conserve heat. Endotherms use their circulatory systems to help maintain body temperature. Vasodilation brings more blood and heat to the body surface, facilitating radiation and evaporative heat loss, which helps to cool the body.
-Properties that can be observed without changing the identity of the object or substance
-Color, shape, size, density
That is an ionic bond.
Ionic bonds are the type of bonds where there is transfer of an electron from one atom to another. The electron is removed from one atom and attached to another.
An example is salt, which is composed of two elements namely sodium and chlorine. Sodium readily gives up one its electrons and chlorine readily accepts it. Before sodium loses the electron, it has a positive charge and after the electron is gone it becomes negatively charged.
Chlorine on the other hand is positively charged before accepting the electron but after it does so, it becomes negatively charged.
These opposite charges attract the two elements together to form a relatively strong ionic bond.
