When can I introduce them?

[nuts4hotwheels]

I have 4 chickens that are 6 weeks old and two that are 2 weeks old. How old do the younger ones need to be before I house them together outside? I put the older ones outside at 3 weeks old. Will the little ones be okay at 3 weeks old with a 4 week age gap?

 

[can you hear me now?]

for me I try to make sure the younger ones have a size to them that the older ones wont peck them till they kill them.