I believe the answer you're looking for is 10
Atomic number = 127 – 53=74 neutrons
IBM and others are using copper instead of aluminum in the most powerful computer chips they manufacture. Because of copper's superior electrical conductivity, this technology enables conductor channel lengths and widths to be significantly reduced.
Mutualism! The tree provides a home and food for the ants, while the ants protect the tree :)
The answer would be metal