Apparently, I didn't do enough reading! Thank you so much for your input, btw. It's far easier to just downvote, and I appreciate you taking the time to give me feedback.

If floating point values are allowed, probably up to two decimals, I think I'll need a error margin. What I'm not too sure of is what the error margin should be.

Ok! I will give it a try. Thanks for the suggestion!

Very cool! How does this work?

JS! Sorry for not clarifying. This is what I'm throwing! (I don't have a lot of experience with error handling so I'm sure it must be something silly but I haven't been able to figure it out!)

function EmptyMolecule(){
 throw {
        name: "EmptyMolecule",
        level: "Show Stopper",
        message: "Error detected",
        htmlMessage: "Error detected",
        toString: function(){ return this.name + ": " + this.message}
    };
};

Hey, there! Great Kata! I'm having trouble with one of the exceptions. I get this error in one of the tests: "Should have throw an EmptyMolecule exception but was: EmptyMolecule: Error detected". I'm not quite sure how to format the error so the test will catch it. Thank you so much!