What are some components of the hydrosphere

1) which of the following is the best example of a physical change? a) sugar dissolving in tea b) firefly glowing 2) in the combustion of ethane, what is/are the reactants? c2h6 + o2 ==> co2 + h2o a) c2h6 and o2 b) co2 and c2h6

An object displaces 652 ml of water. the volume of the object is: 0.652 cm³ 6.52 cm³ 65.2 cm³ 652 cm³

I’m an electrically neutral atomic any element, there are equal numbers of