Which is an element?

A. A carbon dioxide molecule

B. A copper pipe

C. Phosphorous and lithium joined together

D. An alloy of copper and iron

Jose and eric were given four samples in lab. the results of their analysis are shown in the table. based on the data they collected, which sample is most likely a metal?

Which of the following statements is true about energy quantization at the atomic level? electrons in the outermost orbits are the most stable. electrons in all the orbits around the nucleus have the same amount of energy. electrons in the orbit closest to the nucleus have the least amount of energy. electrons absorb or release the same amount of energy independent of the energy levels.

Which of the following statements best explains why chemistry is testable a) it can measure data by experiments b) it cannot add new evidence c) it cannot be verified d) it is biased