Question

based on its location on the periodic table, which metal is likely to be less reactive than rubidium and more reactive than calcium?
potassium (k)
cesium (cs)
magnesium (mg)
titanium (ti)

Explanation:

To solve this, we use the periodic table's reactivity trends for metals. Alkali metals (Group 1) are more reactive than alkaline earth metals (Group 2). Reactivity increases down Group 1 and generally decreases across a period. Rubidium (Rb) is in Group 1, Period 5. Calcium (Ca) is in Group 2, Period 4. We analyze each option:

• Potassium (K): Group 1, Period 4. Reactivity of Group 1 metals: Cs > Rb > K > Na > Li. So K is less reactive than Rb. For Group 2, Ca is in Period 4. Group 1 metals (like K) are more reactive than Group 2 metals (like Ca) because Group 1 has 1 valence electron (easier to lose) vs. Group 2's 2. So K is more reactive than Ca. This fits.
• Cesium (Cs): Group 1, Period 6. Cs is more reactive than Rb (reactivity increases down Group 1), so it can't be less reactive than Rb. Eliminate.
• Magnesium (Mg): Group 2, Period 3. Mg is less reactive than Ca (reactivity increases down Group 2: Ba > Sr > Ca > Mg > Be). So Mg is less reactive than Ca, not more. Eliminate.
• Titanium (Ti): Transition metal, Period 4, Group 4. Transition metals are less reactive than alkali/alkaline earth metals. Ti is less reactive than Ca. Eliminate.

Answer:

A. potassium (K)