A new element is discovered with an atomic mass number of 300. Part 1: If it has 180 neutrons, how many protons does it have? Part 2: After some time, scientists are able to synthesize 1 gram of this...

A new element is discovered with an atomic mass number of 300. Part 1: If it has 180 neutrons, how many protons does it have? Part 2: After some time, scientists are able to synthesize 1 gram of this new element. After 6 months, only 80% of it remains. What is its half-life and its average life? What is its radioactive decay constant?