Aragonite, with a density of 2.9 g/cm3, has exactly the same chemical composition as calcite, which has a density of 2.7 g/cm3. other things being equal, which of these two minerals formed under higher pressure?

Aragonite is most likely be formed under high pressure.

Explanation:

Relating the densities of Aragonite and Calcite which both has the same chemical composition, it shows that the density of Aragonite is more than Calcite which says to some large extent that there is every possibility that Aragonite is most likely to be formed under high pressure.

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

im not exactly sure but i think its b!