It is far more difficult to make a perfect copy of an analog wave because a.) analog waves travel at speeds too great for modern technologies to use. b.)the exact value of any one piece of information is not clearly defined. c.) each individual piece of information is either a 0, a one, or a two. d.) most analog waves have wavelengths that are too long to reproduce in copies

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.

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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.