How do you know what units the volume and mass should be in when doing the calculations for molar concentration questions ex. A solution is prepared by dissolving 5.18 * 10 ^23 molecules of gaseous hydrogen sulfide in enough water to prepare a 300mL solution. What will be the amount concentration of this solution?

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.