"recognize " and "realize"
I have some sentence:
1.I didnt realize you were so unhappy.
2.The moment I saw her I realized somethign was wrong.

3.They recognized the need to take the problem seriously.
4.It was recognized that this solution could ony be temporary.
what I wanna ask is that could the "realize" and "recognize" here replace each other as the meaning what I think is "aware".

Question

"recognize " and  "realize"
I have some sentence:
1.I didnt realize you were so unhappy.
2.The moment I saw her I realized somethign was wrong.

3.They recognized the need to take the problem seriously.
4.It was recognized that this solution could ony be temporary.
what I wanna ask is that could the "realize" and "recognize" here replace each other as the meaning what I think is "aware".

Answer

You could replace recognize, but not realize.

When you realize something, it means that finally understand something.
When you recognize something, it means that you have seen something before and it looks familiar to you.

Answer

In your examples, a form of "aware" can be substituted for both:
1.I wasn't aware that you were so unhappy.
2.The moment I saw her I became aware that somethig was wrong.
3.They became aware of the need to take the problem seriously.
4 They were aware that this solution could ony be temporary.