Zener diode
Transistor
Triac
Diac
0.1 to 0.5 volt
0.5 to 1 volt
3 to 18 volt
1 to 3 volt
Lead
Silicon
Titanium
Platinum
One
Two
Four
Three
10-3 farad
10-6 farad
10-9 farad
10-12 farad