Bread left out on a counter and allowed to mold
Each aluminium ion should have a charge of +2, because the sum of oxidation numbers must be zero.
The uncharged aluminium atom must lose two electrons to become an ion with +2 charge.
what has to happen to an uncharged aluminum atom so that it will bond with oxygen?
It has to lose electrons to become positively charged, so it can attract a negatively charged oxygen ion
Answer:
Scientists believe that the different types we know emerged as early humans adapted to infectious diseases.
Explanation:
Different human blood types probably emerged to ward off infectious diseases. The incompatibility of some blood types, however, is only an "accident" of evolution. But this is a relatively recent problem, since blood transfusion has been around for only a few hundred years.
There are four main blood types. The oldest is B, which must have originated about 3.5 million years ago - it existed even before the human species evolved from its hominid ancestors, from a genetic mutation that modified one of the sugars in the surface of red blood cells.
Approximately 2.5 million years ago, mutations inactivated sugar, resulting in type O blood, which has neither type A nor B. sugar. AB blood, as it is easy to suppose, is covered by both sugar A and sugar by B.
Do not use water, alcohol or acetone as the oil is insoluble to these solvents. To remove other oily substances, i recommend using the detergent called Wisk and prepare a solution of 1 part Wisk to 100 parts water I usually use it . Hope it helps
