I have a quiz and the time is unlimited. This sentence appeared to me. The timer can only start after the setup process is finished.
What does this timer mean? Why does that time appear unlimited, please explain hi

Your 249 ml cup of coffee is too hot to drink when served at 82 degree celsius. what is the mass of an ice cube taken from a -21 degree celsius freezer, that will cool your coffee to a pleasant 54 degree celsius. specific heat of the water is 4190 j/kg c, specific heat of ice is 2090 j/kg c, heat of fusion of ice is 3.33 x 10^5 j/kg

What property is a characteristic of a substance that can be observed and does not change the identity of the substance

Could someone me find the answer to this problem.