It is very simple to identify whether a clam is alive or dead. It takes a lot of effort to use a knife to pry open the gap in the middle of a clam that is not dead. However, you can pry open a dead clam and the mucus is very thick and smelly. If you are not at ease, it is best to do as I say, because I grew up by the sea, and this is how I check and deal with all kinds of clams that I am worried about.