Electromagnetic energy travels in waves. When we describe electromagnetic waves, we often talk about the wave's length and frequency. Which of these statements accurately
describes the relationship between the wavelength and frequency of an electromagnetic
wave?

A: If wavelength increases, frequency increases.
B: If wavelength increases, frequency decreases.
C: If frequency remains constant, wavelength increases.
D: If wavelength remains constant, frequency increases.

yes it is balanced

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.  

it is b that is the answer.