Express 45 minutes as a percentage of 3hours 20 minutes

What is the mass of each element in a 324.8 sample of co2

Using data from seismic waves, geologists have learned that earth’s interior is made up of several

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