Question

checkpoint 1:
locate cs, sr, rb, and ba on the periodic table.
which would you expect to be the most
reactive?
rb
sr
cs
ba

Explanation:

• Reactivity of metals increases down a group in the periodic table.
• Cs (Cesium) is in Group 1 (alkali metals), Rb (Rubidium) is also in Group 1 but above Cs.
• Sr (Strontium) and Ba (Barium) are in Group 2 (alkaline earth metals).
• Alkali metals are more reactive than alkaline earth metals.
• Among Cs and Rb (both alkali metals), Cs is lower in the group, so more reactive.

Answer:

Cs