17. A scientist determines an unknown metallic sample to have 77 protons and 77 electrons with a mass number of 192. How many neutrons does one
metal atom contain?
![17 A scientist determines an unknown metallic sample to have 77 protons and 77 electrons with a mass number of 192 How many neutrons does one metal atom contain class=](https://us-static.z-dn.net/files/d5f/70e5cf7aedc8df9f820d404680b20fc2.png)