A. the wax is a both; 1. physical change-solid to liquid.
2. chemical change- burned to CO2 + H20 + heat + carbon as seen as black on the rod
b. the wick is neither; the wick does not change, just provides conduit for wax to flame
c. the glass rod is physical change; the carbon is only deported
HOPE THIS HELPS, IVE ALSO LEARNING BEEN LEARNING THIS RECENTLY
4.88x10^20 H2O2 molecules
Answer:
Explanation:
The correct measurement is .710 s which is equal to .71 s so second measurement that is 0.71 s is most accurate measurement .
B. 0.71s is the most accurate .
Precision depends upon measuring instrument . Measurement by highly precise instrument has greater precision .
The measurement of 0.75 ± 0.002s must have been taken from high precise instrument because it is capable of making measurement upto 3 decimal points .
Hence
C 0.75 ± 0.002s is most precise measurement .
The chemical contractor has to retrieve the chemical and a identification analysis would have to be conducted