Group 7 elements (halogens)
Answer:
NaBr
Explanation:
When AgBr is dissolved in water, the following equilibrium is set up in solution;
AgBr(s)⇄Ag^+(aq) + Br^- (aq)
If we dissolve NaBr in the water, a common ion (Br^-) is now introduced into the system. This increases the concentration of Br^- and favours the reverse reaction hence more AgBr is precipitated. This is known as common ion effect.
The atomic number of an element gives the element it's identity. This is also known as the number of protons within an element. If you have the number of protons but don't know the element's atomic mass, add the protons and neutrons to get the mass number.
I hope this helped!
wave length is what he decreased
