An element is the simplest form of matter that has a unique set of properties. Examples of well-known elements include oxygen, iron, and gold (see the figure below). Elements cannot be broken down into a simpler substance.
Explanation: Happy to help
Answer:
sorry if i get it wrong its been a long time since i did this i believe its nucleus
Answer: the blue squares are B and the white squares are BB
The remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.
Mold fossils
Cast fossils
Trace fossils