T/F About Science

1. false. the bunsen burner after strike back is very hot. touching it would be burnt and hurt.
you should close the gas tap immediately, shutting down the burner, and re-lit it after proper cooling (of course close the air hole before re-litting).

2. false.
the liquid may be contaminated ("polluted") after pouring into test tube. returning the liquid to reagent bottle may contaminate the chemicals in whole reagent bottle.