The property trends in general on moving from left to right in a period of the periodic table are :
- Number of valence electrons — increases by one
- Atomic radius — decreases.
- Ionization potential — increases.
- Electron affinity — increases (exception, electron affinity is zero for noble gases).
- Non-metallic character — increases.
- Metallic character — decreases
- Electronegativity — increases (with the exception of noble gases, they have complete octet so do not attract electrons to itself).