Joe is concerned about the carbon dioxide emissions from his daily commute and the impact that it is having on global warming. In his daily drive to and from work Joe travels 60 miles and gets 20mpg. Joe would like to know how many grams of carbon dioxide is emitted from his driving each 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.  

the correct answer would be d. hope this !