Holly has an unknown substance in a beaker. she wants to determine the relative ph of the unknown substance. she places a piece of blue litmus paper into the substance, and the litmus paper turns red. the substance in the beaker

Blue litmus paper turns red in the presence of an acid. Therefore, it can be assumed that the substance in the beaker is an acid.

Acids have a pH level of less than 7. Consequently, it can be assumed that the substance has a pH level less than 7.

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