Which type of substance yields hydrogen ions h in an aqueous solution?

Acids dissociate in water to release a proton. The proton then combines with water to form a  hydronium ion.  

HCl, hydrochloric acid dissociates in water to release proton H⁺ and chloride ion Cl⁻

HCl → H⁺ + Cl⁻

H⁺ + H₂O → H₃O⁺

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

answer: a tank of height h is filled with water and sits on the ground. water squirts from a hole at a height y above the ground and has a range r. for two y values, 0 and h, r is zero. determine the value of y for which the range will be a maximum.

explanation: