In Group 1 elements, how does reactivity change as you go down the group?

In Group 1 elements, how does reactivity change as you go down the group?

• A. Increases
• B. Decreases
• C. Stays the same
• D. Varies

Answer: (A)

Group 1 elements are metals that react by losing their single outer electron. As you go down the group, the atoms get larger and more inner electron shells shield the outer electron from the nucleus. This reduces the attraction the nucleus exerts on that outer electron, so it’s easier to remove. Because reactivity in these metals hinges on how readily they can lose that electron, reactivity increases down the group. In practice, this means light metals like lithium react slowly with water, while heavier ones like cesium react very violently. The other options would contradict the observed trend: reactivity does not stay the same or decrease; it increases as you move down.

Group 1 elements are metals that react by losing their single outer electron. As you go down the group, the atoms get larger and more inner electron shells shield the outer electron from the nucleus. This reduces the attraction the nucleus exerts on that outer electron, so it’s easier to remove. Because reactivity in these metals hinges on how readily they can lose that electron, reactivity increases down the group. In practice, this means light metals like lithium react slowly with water, while heavier ones like cesium react very violently. The other options would contradict the observed trend: reactivity does not stay the same or decrease; it increases as you move down.