Electron configurationIB MYP Sciences: Mind map

Exam questions on Electron configuration

1. A museum in Lagos is building a display of the first twenty elements. Each element card shows its electron configuration, written as the number of electrons in each shell from the inside outwards (for example, lithium is 2,1).
   An element X has the electron configuration 2,8,6. State the group and the period of X, giving a reason for each.2 marks
2. A science teacher in Nairobi shows her class a neon sign and a sodium street lamp. She tells them that a neon atom has the electron configuration 2,8 and a sodium atom has the electron configuration 2,8,1.
   Explain, in terms of electron arrangement, why neon is unreactive but sodium is reactive.2 marks
3. A student in Mumbai writes out electron configurations for ten elements and looks for patterns. Her results: lithium 2,1; beryllium 2,2; boron 2,3; carbon 2,4; nitrogen 2,5; oxygen 2,6; fluorine 2,7; neon 2,8; sodium 2,8,1; magnesium 2,8,2. She proposes the hypothesis: "The number of electrons in the outer shell of an atom is equal to the period number of its element."
   Describe the pattern in the student's data from lithium to neon, and what happens at sodium.3 marks