When two objects are touching, thermal energy transfers from...
hotter to colder substances?
Or
colder to hotter substances?

According to the laws of thermodynamics, Molecular movements of particles will tend to move into state of lower energy and this would mean that knowing the vibrational and translational energy of complex molecules will lose and give off energy usually in the form of heat but also sound and other transferable mediums it will tend to become less energetic and this mobile indicative of colder objects, if examining the average Molecular kinetic energy and bond energies of the compounds in question.

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

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.