There are 4 molecules racing to get across a typical cell membrane. contestants: a. c6h12o6, b. co2, c. cl- and d. ch3ch2ch2cooh (a fatty acid). predict the order they'd make it across

b.CO2

d.CH3CH2CH2COOH (a fatty acid)  

c.Cl-

a.C6H12O6

Explanation:

The cell membrane is permeable to gases and fatty acids, as they are non polar and small molecules. Those goes throught the cell membrane with no need of a canal or carrier.

The polar and big molecules needs a canal (as Cl-) or carrier (as C6H12O6) to get the cytoplasma.

the answer is a and have a great day

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.