How to say these sentences in German?
Hallo.
How to say these sentences in German?

1- I'm familiar with this subject. ( for example : chemistry subject in the university ).
2- The nail penetrates the wood. ("dringen" or "eindringen").
3- There is a security breach / security chaos. (for example; many murders start to occur, and the police aren't able to help).
4- If memory serves me correctly (after saying a thing, that happened a long time ago).
5- If I am not mistaken about the word (after saying a word, that you're not sure if it's correct).
6- Is that raw or cooked meat.
7- He retreated from his actions. (when someone was doing bad things , but decided to stop).

Vielen vielen Dank im Voraus.

Question

How to say these sentences in German?
Hallo.
How to say these sentences in German?

1- I'm familiar with this subject. ( for example  : chemistry subject in the university ).
2- The nail penetrates the wood. ("dringen" or "eindringen").
3- There is a security breach / security chaos. (for example; many murders start to occur, and the police aren't able to help).
4- If memory serves me correctly (after saying a thing, that happened a long time ago).
5- If I am not mistaken about the word (after saying a word, that you're not sure if it's correct).
6- Is that raw or cooked meat.
7- He retreated from his actions. (when someone was doing bad things , but decided to stop).

Vielen vielen Dank im Voraus.

Answer

Just some small changes besides the sentences from Maximilian:
1. Ich kenne mich in diesem Fach aus
3. Es gibt einen Aufstand
5. wenn ich mich nicht irre

Answer

1. Ich kenne mich mit diesem Fach aus 
2. Der Nagel dringt in das Holz ein. 
3. Es gibt einen Ausnahmezustand /  Es gibt eine Sicherheitslage / Die Sicherheit ist nicht gewährleistet 
4. Wenn ich mich richtig erinnere 
5. 
6. Ist das rohes oder gekochtes Fleisch? 
7. Er hat sich von seinen früheren Taten distanziert / Er hat sich geändert / Er hat sich gebessert