When performing your experiment, you add your first drop of oleic acid/benzene solution, and a lens forms immediately. what is wrong with your setup, and how can it be corrected?

What's wrong with this setup is the substrate on which you have positioned the drop is "dirty and unclean" meaning it is not being dampened by the solution. This action can be corrected by comprehensively cleaning the substrate where the drop will be positioned.

hi,

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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.