What are the two parts of a longitudinal wave and what happens at each point

Asample of rose gold is: 12.0 g gold, 5.0g silver, and 7.0 g copper. what is the percent copper in the sample?

Which traits do human embryos have that link them to a common ancestor with fish and reptiles? a. scales and tail b. gill slits and scales c. tail and gill slits d. hair and tail

98 ! and brainliest plz ! the below reaction can be categorized as more than one type of reaction. which reactions are these, and what are the types of reactions?