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(n

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

the answer is:  

line graphs show patterns in data with variables that change over time; whereas, circle graphs show data as parts out of a whole (such as out of 100%).

the awnser is group 12