Would Kurt Cobain have benefited from Project Semicolon?
Project Semicolon is an American nonprofit organization known for its advocacy of mental health wellness and its focus as an anti-suicide initiative. During the last years of his life, Cobain struggled with heroin addiction and chronic health problems such as depression. Cobain died at the age of 27 from apparent suicide by gunshot.
The answer is yes.

Does Düsseldorf have only a small number of smoggy days each year?
Mercer's 2012 Quality of Living survey ranked Düsseldorf the sixth most livable city in the world. Clean air is an important attribute for a livable city. Smog is a term for air pollution.
The answer is yes.

Is 500GB USB device enough to save 10 hours of Netflix shows a day?
5 hours of Netflix programming uses up approximately 1 TB of data. 1 TB is equal to 1000 GB of data.
The answer is no.

Would a modern central processing unit circuit chip fit on a housekey?

A CPU circuit chip is about an inch across. A housekey is generally less than a half-inch across.
The answer is no.