Protons and neutrons make up the nucleus and electrons orbit them in a cloud.Answer and Explanation: The mass number is not the number of protons. The mass number is the number of protons added to the number of neutrons. The mass number can be found...Become a member and unlock all Stu...
百度试题 结果1 题目6 An atom of element Q contains 19 electrons, 19 protons and 20 neutrons.What is Q? B A calcium B potassium C strontium D yttrium 相关知识点: 试题来源: 解析 B 反馈 收藏
Protons are subatomic particles that, along with neutrons, comprise the nucleus or central portion of an atom. The rest of the atom consists of electrons that orbit the nucleus, much as Earth orbits the sun. Protons can also exist outside an atom, in the atmosphere or in space. In 1920,...