Chickens not getting along with new chick

[Kevomxracer]

So I had 2 new chicks that I got when they were 2 days old. And I had them in an old 10 gallon fish tank with a heat light, bedding..etc. and one if the chicks died so the 1 that I have left is about 4 weeks old now and it seems lonely so I went to put it in the coop with my other 4 month old chickens( Rhode Island Red, white leghorn, 2 feather footed bantams). And they all ran up to it and starred at it, like they wanted to kill it. So when I picked the chick up to take it out the 1 of the chickens pecked it right in the head with aggression and then fluffed up in anger. What am I supposed to do I can't keep the chick in the old 10 gallon tank forever. Does anyone know if/when the other chickens can get along with this baby chick?

 

[CHICKEN CRAZY1]

Probally at about 4 to 5 months of age or less,
Maybe when it has lost all his/her down.

 

[CHICKEN CRAZY1]

And they all ran up to it and starred at it, like they wanted to kill it.

This is called a pecking order.
The chick is new and the chickens have never seen it before and they want to establish themselves as the bosses of the coop.
Put the chick in the coop in the cage where it can see the chickens.
if they can see it too,when it is time to put the chick out with the chicken, (when it is old enough)there will be less violence.