Answer:
Iron and Oxygen
Explanation:
Fe is Iron and O2 is Oxygen
They will repel one another because opposites attract, but like charges will repel.
Answer:
Conductivity meter
Explanation:
All of the other choices measure pH and can tell you when the pH changes, which is how you know the neutralization reaction has occurred. A conductivity meter does not measure pH.
Number 2 lower entropy and higher entropy