The backspace key on my keyboard isn't working properly

[MarieSoleil]

I have a ASUS chromebook and the backspace key is almost stiff and I have to push it multiple times to erase anything. It's really annoying and I don't know what could have caused it. It's the only key that is doing this and I know I haven't spilled anything on it. It was in my bag when I slipped and hit the ground but would that mess up the one key and nothing else? I just want to know if there is anything that could have caused this and if there is something I could do to fix it.