If you are using the unit kelvin, you are measuring the average

kinetic energy of molecules.

rate of reaction of particles.

mass of ionic compounds.

volume of a sample of gas.

If you are using the unit Kelvin, you are measuring the average KINETIC ENERGY OF MOLECULES.

Kelvin is the unit for measuring the absolute temperature of objects. Temperature refers to the degree of hotness or coldness of a body. The temperature of a body depends on the amount of heat that is applied to it, the amount of heat applied determine the value of kinetic energy that the particles of the body will possess; the higher the heat applied the higher the kinetic energy of the particles and vice versa.

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