8. The relative abundance and atomic masses are 69.2% for copper-63 and 30.8% for copper-65. Calcula the average atomic mass of copper. SHOW YOUR CALCULATIONS (WORK!!

pure substance: iron,copper

impure substance: water,charcoal

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation:

practical process described pest part of scientific investigation.

because practical knowledge is powerful then therotical knowledge.