A metal conducts heat in a similar way to electricity so, as you touch it, it draws heat from your body and makes your hand feel cold. Plastics don't have to conduct heat so they don't draw heat from your body as efficiently; that's why a piece of plastic
feels than a piece of metal even if it's at the same temperature.
A) long-chain molecules; warmer
valence electrons; colder
B) free electrons, warmer
D) a crystalline lattice; colder

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

a) the particles of the chair are strongly held together.