Is silicon reactive?
Silcon is not very reactive, like for example Sodium or Potassium, but it does react and when it does it tends to form silicates.
No. Chlorine is more reactive than silicon. This is because Chlorine has 7 valence electrons; nearly a full outer shell, while silicon has only 4 valence electrons. An element needs 8 valence electrons to react, and Chlorine only needs one more valence electron before it can react, unlike Silicon, which needs 4.
Silicon does not form ionic compounds containing Si cations. It is after all a non-metal. There are some "odd" compounds called silicides binary compounds of metals with silicon but generally these are not ionic, only those with the more reactive metals have ionic nature, silicon forming cluster anions (Zintl compounds) such as Si44- (isoelectronic with P4 molecule)