The following table lists the speed of sound in various materials. use this table to answer the question.

substance speed (m/s)
glass 5,200
aluminum 5,100
iron 4,500
copper 3,500
salt water 1,530
fresh water 1,500
mercury 1,400
hydrogen at 0°c 1,284
ethyl alcohol 1,125
helium at 0°c 965
air at 100°c 387
air at 0°c 331
oxygen at 0°c 316
sound will travel the slowest in

air
glass
aluminum
water