Question

elements are organized on the periodic table based on their properties. which statement correctly pr
rubidium (rb) is more reactive than strontium (sr) because strontium atoms must lose more electr
sodium (na) is more reactive than magnesium (mg) because sodium atoms must gain more electro
calcium (ca) is less reactive than potassium (k) because potassium atoms must lose more electron
beryllium (be) is less reactive than lithium (li) because beryllium atoms must gain more electrons.

Explanation:

• For metals, reactivity increases down a group (due to larger atomic size, easier to lose electrons) and decreases across a period (from left to right, as nuclear charge increases, harder to lose electrons).
• Rubidium (Rb) is in Group 1 and Strontium (Sr) is in Group 2. Rb is more reactive than Sr because Group 1 metals are more reactive than Group 2 metals in the same period. Group 1 metals have one valence electron to lose, while Group 2 have two. It is easier for Group 1 metals to lose their single valence electron.
• Sodium (Na) is in Group 1, Period 3 and Magnesium (Mg) is in Group 2, Period 3. Na is more reactive than Mg (Group 1 more reactive than Group 2 in the same period), not because of gaining electrons (metals lose electrons in reactions).
• Calcium (Ca) is below Magnesium (Mg) in Group 2. Ca is more reactive than Mg (reactivity increases down a group for metals), not less.
• Beryllium (Be) is in Group 2, Lithium (Li) is in Group 1. Li is more reactive than Be (Group 1 more reactive than Group 2 in the same period). Beryllium atoms lose electrons (metals lose electrons), and the reactivity difference is mainly due to group position (Group 1 vs Group 2) not the number of electrons gained (metals lose electrons).

Answer:

Rubidium (Rb) is more reactive than strontium (Sr) because strontium atoms must lose more electrons.