As I push down the plunger on a sealed syringe, the pressure begins to
push back against me. Who's law is this?

Boyle's Law

Charles' Law

Gay-Lussac's Law

Avogadro's Law

Boyle's Law

Explanation:

This is a simple Boyle's law at work in this scenario.

Boyle's law is one of the gas law and it states that "The volume of a fixed mass of gas varies inversely as the pressure changes if temperature is constant".

This law was proposed by Robert Boyle.

This is clear cut practical of the Boyle's law.

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-