I bought some razor clams today and all of them were open with their "tongue" or meat coming out of the shell. When I got home I noticed they had a really strong smell to them. This is the first time I've bought razor clams....so how do I know if they are safe to eat?
There are two types of razor clams. Since you are in the US according to your profile, I am guessing you have the type from the Pacific Northwest, which look like this (picture from Washington Fish and Wildlife):
It is normal for the razor clam to not completely fit into its shell; in particular, the digger or "foot" will extend from the shell.
According to Piscatorial Pursuits (I couldn't make that name up):
The neck tips are very tough and give off a very strong scent.
The Washington Department of Fish and Wildlife has a detailed page on cleaning and preparing the clams, with pictures. Note that they indicate (emphasis original):
During cleaning, you may find small "pea crabs" or flatworms inside the body of the clam. NEITHER OF THESE AFFECTS THE QUALITY OF THE RAZOR CLAM MEAT.