How many alleles are there for the main blood types found in the human population?
two alleles
three alleles
four alleles

Hey guys so i need to know what is _nh3+> nh4oh ~chemistry~

Which is true about metals used for jewelry, such as platinum and gold? a. they have low flammability. b. they have low reactivity. c. they have high flammability. d. they have high reactivity.

Which change will decrease the number of effective collisions during a chemical reaction? a. adding a catalyst b. increasing the surface area c. decreasing the temperature d. increasing the reactant concentrations e. increasing the volume of the reactants