OK, try to pull it together based on the information you've been given. Would it make sense if the number of protons and electrons were different? So maybe you can discount that info. What info can you use to determine atomic number? And what can you use to determine atomic mass. And is there a reference form you can use those numbers with? You may have come across one of those ... periodically.
*[EDIT] my late night spelling and grammar suck*