4.An analysis to determine the percent weight of Cu in an ore sample gives the following results: 16.54, 16.30, 16.64, 16.67, 16.70, and 16.49 % w/w. Calculate the confidence
interval of the mean at 90% C. L.

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.

a corroding iron, if that's one of your choices

c) should be the answer.