Why is sodium more reactive than lithium in water?

Question:

Why is sodium more reactive than lithium in water?

Answer:

Sodium is more reactive than lithium in water because the valence electrons in sodium are farther away from the nucleus, making them easier to remove.

When sodium (Na) is added to water, it is more reactive than lithium (Li) because the valence electrons in sodium are farther away from the nucleus compared to the valence electrons in lithium.

This means that the valence electrons in sodium are less tightly held by the nucleus and are more easily removed. To understand this, let's compare the atomic structures of sodium and lithium. Sodium has an atomic number of 11, meaning it has 11 electrons. The outermost electron in sodium is in the third energy level. On the other hand, lithium has an atomic number of 3, with the outermost electron in the second energy level.

The valence electrons in sodium are in a higher energy level, which makes them farther away from the nucleus. This weaker attraction between the nucleus and the valence electrons in sodium allows them to be more easily removed when sodium is added to water. In contrast, the valence electrons in lithium are closer to the nucleus and more tightly held, making it less reactive in water compared to sodium.