Which statement defines rate-determining step in a chemical reaction?

a the slowest step that determines the speed (rate) of the overall reaction
b the fastest step that determines the speed (rate) of the overall reaction
c an experiment that is performed to determine the rate law
d all the reactants in all the steps of a reaction mechanism

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance