When mixing 5.00 mL of an AgNO3 0.0200 molL-1 solution with 20.00 of a solution of NH3 0.540 molL-1, the ag(NH3)2+ complex is forming. The concentration of Ag+ ions in molL-1 after the reaction reaches equilibrium shall be: Data: log β2 = 7.1

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.  

that's what i got you can count the number of atoms

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3