what is the symbol for the following ion electronic structure: 1s22s22p63s23p63d104s24p64d105s2 with an atomic number of 50?

It depends on the subject for me. some exams are easier than others so i usually go through it and answer questions i know based on my general knowledge, then double check after. going through the lesson can a lot  because the exams can be  very lesson-specific, but sometimes they are ridiculously long so a lot of people don't take the time. i did find that, when i went through the lessons, i was making 100's on my exams vs strictly using + the internet and  i make 90's. 

The answer is a or b

2.a rent payment4.renters insurance5.a security deposit6.utility paymentsare the correct  answers