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Smog is the term used to describe the combination of fog and smoke

Alarge marble is dropped in a graduated cylinder with 35ml of water in it. the water level increases to 49ml. what is the volume of the marble

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