Solution A solution B
Does a
precipitate form
when A and B
are mixed?
empirical
formula of
precipitate
manganese(II) bromide
zinc sulfate
yes
no
0
ammonium bromide
sodium hydroxide
O yes
no
potassium sulfide
copper(II) sulfate
yes
no

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.  

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).

the ratio of the conjugate base to the acid required to attain the desired ph.