Question

how does the reactivity of neon (atomic number 10, period 2, group 18) differ from that of sodium (atomic number 11, period 3, group 1)? explain your reasoning based on the properties of neon and sodium that you can infer based on their atomic numbers, periods, and groups. (4 points)

Explanation:

Step1: Recall electron - configuration and reactivity concepts

Neon has a full outer - shell electron configuration (2, 8) as it is a noble gas in group 18. Its outermost energy level is completely filled, making it very stable and unreactive.

Step2: Analyze sodium's electron - configuration

Sodium has an electron configuration of (2, 8, 1). It has one valence electron in its outermost shell. Sodium wants to lose this single valence electron to achieve a stable electron configuration like the nearest noble gas (neon). So, it is highly reactive.

Step3: Consider periodic trends

In the periodic table, elements in group 1 (alkali metals like sodium) are highly reactive because they have one valence electron and readily lose it to form a + 1 ion. Elements in group 18 (noble gases like neon) are inert due to their stable electron configurations.

Answer:

Neon is unreactive because it has a full outer - shell electron configuration (2, 8), which is a stable state. Sodium is reactive because it has one valence electron (electron configuration 2, 8, 1) and wants to lose this electron to achieve a stable electron configuration like neon. Sodium is in group 1 (alkali metals) which are highly reactive as they readily lose their single valence electron, while neon is in group 18 (noble gases) which are inert due to their stable electron arrangements.