would tearing aluminum foil be a physical change

Which formula can be used to calculate the molar mass of ammonia (nh3)? molar mass of n + molar mass of h 3 × molar mass of n + molar mass of h molar mass of n + 3 × molar mass of h 3 × molar mass of n + 3 × molar mass of h

In france, grapes are 1.95 euros per kilogram. what is the cost of grapes, in dollars per pound, if the exchange rate is 1.14 dollars/euro? (2.6)

How many absorptions would you expect to observe in the 13c nmr spectra of the following molecules? a) 3-chloropentane b) cis-4-methyl-2-pentene