Organize the following materials: pen
staple
board
pencil
paper
desk
marker
paper clip
safety pin

Made of Plastic; Pen, marker

Made of wood/leaf; board, pencil, desk, paper

Made of metal; staple, desk, paper clip, safety pin

Carbon-14 has a half-life of 5,730 years and most igneous rock is older than that.

The answer to this will be from your lab notes/procedure. it would be best to ask another student who participated in the lab as we do not know what was done, what enzyme or if the temperature is celsius or fahrenheit. if i were to guess though i'd say the rate stopped due to enzyme denturing at high temperature