summarize:

Neon (Ne) and sodium (Na) exhibit very different reactivities due to their positions in the periodic table, characterized by their atomic numbers, periods, and groups.
1. **Group and Reactivity:**
- **Sodium (Na)** is in Group 1, which is known as the alkali metals. These elements are characterized by their high reactivity, particularly with water and halogens, due to their single electron in their outermost shell. This one valence electron makes sodium keen to lose it, thus forming a positively charged ion (Na⁺) and achieving a more stable electron configuration similar to that of noble gases.
- **Neon (Ne)**, on the other hand, is in Group 18, which comprises the noble gases. Noble gases are known for their lack of reactivity because they have complete outer electron shells. Neon has eight electrons in its outer shell, which fulfills the octet rule, making it highly stable and unlikely to engage in chemical reactions under normal conditions.

2. **Period and Electron Configuration:**
- Sodium is in Period 3, meaning it has three electron shells. The electron configuration of sodium is 1s² 2s² 2p⁶ 3s¹. The presence of one electron in the 3s orbital leads to its reactivity, as it can readily lose that electron to form a Na⁺ ion.
- Neon is in Period 2, with the electron configuration 1s² 2s² 2p⁶. Its full outer shell (2s and 2p subshells filled) makes it stable and nonreactive. The filled valence shell means that neon does not easily gain, lose, or share electrons.

3. **Overall Summary of Reactivity:**
- Sodium, due to its single valence electron, is very reactive and readily loses that electron to become stable, leading to various chemical reactions.
- In contrast, neon, with its complete outer shell, is chemically inert and does not participate in reactions under standard conditions.

In conclusion, the reactivity of neon differs significantly from that of sodium due to their complete versus incomplete valence shells, reflecting the fundamental principles behind the properties of elements in different groups of the periodic table.

1 answer

Neon (Ne) and sodium (Na) demonstrate vastly different reactivities due to their positions in the periodic table. Sodium is in Group 1 (alkali metals) and is highly reactive because it has one valence electron that it readily loses to form a Na⁺ ion, achieving stability. In contrast, neon is in Group 18 (noble gases) and is chemically inert due to its complete outer shell of eight electrons, making it stable and unlikely to engage in reactions.

Sodium, located in Period 3, has an electron configuration of 1s² 2s² 2p⁶ 3s¹, while neon, in Period 2, has a configuration of 1s² 2s² 2p⁶. The presence of an unpaired electron in sodium encourages its reactivity, whereas the filled valence shell in neon ensures its nonreactivity.

In summary, sodium's high reactivity stems from its single valence electron, while neon's lack of reactivity is due to its complete outer shell, highlighting the fundamental differences between elements in different groups of the periodic table.