In which of the following situations does light exhibit particle properties? A.
Different materials reflect different colors of light.
B.
Light appears to bend around obstacles in its path.
C.
Light travels in straight lines through uniform materials.
D.
Different materials absorb different colors of light.

screening

explanation:

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.