Which particle has a mass of approximately 1 atomic mass unit?

a) an alpha particle
b) a beta particle
c) an electron
d) a neutron

What material does not melt at any temperature

Measurements that have similar values are: a. usually accurate b. sometimes accurate c. always accurate d. never accurate

Consider a culture medium on which only gram-positive organisms such as staphylococcus aureus colonies can grow due to an elevated nacl level. a yellow halo surrounds the growth, indicating the bacterium fermented a sugar in the medium, decreasing the ph as a result and changing the color of a ph indicator chemical. this type of medium would be referred to as a differential and enrichment culture.