The evidence of chemical changes with an example of each (include all 5)

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

In the space, show a correct numerical setup for calculating the number of moles of co2 present in 11 grams of co2

How does climate change cause the ocean's thermohaline current to slow down?