'Metallic Properties?

Question

I have some question on heating treatment for a metallic item.

For example, if I have two paper clip, where 1 is being HEATED TO GLOWING RED THEN COOLED OFF QUICKLY IN COLD WATER would it be hard and brittle...there if another paper clip is being HEATED TO GLOWING AND LEFT ASIDE TO BE COOLED OFF SLOWLY would it be more flexible

please answer and provide some explanation if possible

Answer 1

The process of heating then rapid cooling is called Tempering.
While it makes the object stronger, it also shatters into small pieces when broken.

The slowly cooled object would be more flexible being it has not been tempered.