Difference between porqué and por que (noun vs preposition + conjunction)

Question 1

Porqué

Answer 1

a reason, a cause

associated article (el, los, un, unos) or other determiner such as possessive adjectives (mi, tu, su, etc.) must agree.

Question 2

I don’t understand the reason for his negative attitude.

Answer 2

No comprendo el porqué de su actitud tan negativa

Question 3

I won’t tell you the reasons for my decision.

Answer 3

No te voy a explicar los porqués de mi decisión

Question 4

Por que

Answer 4

for which, that or why

Question 5

This is the reason why I came.

Answer 5

Esta es la razón por que he venido

Question 6

I am worried that she won’t like it.

Answer 6

Me preocupo por que no le guste