A combination of salt and sugar grains is best classified as a mixture because... A the grains taste different from one another.
B both salt and sugar grains are in the same state of matter.
C no new chemical bonds are formed between the salt and sugar grains.
D a new product is formed when the salt and sugar grains are combined

The teacher is mostly talking about the distillation of a mixture

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na