The waves used by a microwave oven to cook food have a frequency of 2.45 x 10° Hz. Calculate the wavelength
of this type of wave.

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

It would be true sodium reacts with water in a violent way 

Ithink it’s carbon dioxide

Idon't mean to be a smart alec, length of atoms' bonds is the simplest way to define it.