What kind of contaminants relate directly to food, such as bacteria, viruses, Molds or parasites can create toxins? biological contaminants physical contaminants chemical contaminants abrasion contaminants?

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.  

its first and third is your answer i did the qustion the fourth isnt right