Question

has the largest atomic mass
only alkali metal with no stable isotopes
alkaline earth metal with 4 energy levels
most common mass number is 131
metalloid with the smallest mass
only nonmetal in group 14
4 electrons in energy level 5
222 is the most stable isotope
atomic number of 81
84 protons
liquid nonmetal
liquid metal
member of group 7 with no stable isotopes

Answer:

To solve these matching problems, we analyze each clue:

1. Largest atomic mass: Typically, elements like Oganesson (but in common context, maybe Radon? Wait, no—Uranium? Wait, actually, among common elements, Oganesson (but maybe in standard curriculum, Radon? No, wait, the heaviest natural element is Uranium? Wait, no, let's think step by step. Wait, maybe Francium? No, atomic mass: the largest atomic mass element (stable or not) is Oganesson, but in common problems, maybe Radon? Wait, no, let's check each clue:

• Only alkali metal with no stable isotopes: Francium (Fr) (alkali metals: Group 1; Fr has no stable isotopes).
• Alkaline earth metal with 4 energy levels: Calcium (Ca)? No, 4 energy levels: period 4. Alkaline earth (Group 2) in period 4: Strontium? No, period 4: n=4. Alkaline earth: Group 2, period 4: Calcium is period 4? Wait, Ca is period 4 (n=4). Wait, no: period 1: n=1, period 2: n=2, etc. So period 4: n=4. Alkaline earth (Group 2) in period 4: Calcium (Ca) has n=4? Wait, Ca: atomic number 20, electrons: 2,8,8,2. So 4 energy levels. Wait, but Strontium is period 5. Wait, no—Calcium (Ca)? Wait, no, alkaline earth with 4 energy levels: Calcium? Wait, no, period 4: n=4. So Group 2, period 4: Calcium (Ca) has 4 energy levels (n=1,2,3,4). Wait, but maybe Strontium? No, period 5. Wait, maybe I made a mistake. Let's correct:

• Most common mass number 131: Iodine (I) has mass number 131 as a common isotope (I-131).
• Metalloid with smallest mass: Boron (B) is a metalloid, and has low atomic mass.
• Only nonmetal in Group 14: Carbon (C) (Group 14: C, Si, Ge, Sn, Pb; only C is nonmetal).
• 4 electrons in energy level 5: Energy level 5 (n=5) has 4 electrons: element in period 5, Group 14 (since valence electrons: n=5, 4 electrons → Group 14). So Tin (Sn)? Wait, Sn is in Group 14, period 5. Electrons in n=5: 4. Yes.
• 222 is most stable isotope: Radon (Rn) has Rn-222 as a stable (or most stable) isotope.
• Atomic number 81: Thallium (Tl) (atomic number 81).
• 84 protons: Polonium (Po) (atomic number 84, so 84 protons).
• Liquid nonmetal: Bromine (Br) (liquid at STP, nonmetal).
• Liquid metal: Mercury (Hg) (liquid at STP, metal).
• Member of Group 7 with no stable isotopes: Astatine (At) (Group 7, no stable isotopes).

Matching Answers (Key):

• Largest atomic mass: Probably Oganesson (or in some contexts, Radon—but likely a heavy element like Francium? Wait, no, atomic mass: the largest is Oganesson, but maybe in the problem’s context, let's assume:

But to match each:

1. Has the largest atomic mass → Oganesson (or a heavy element, but maybe Francium? No, Francium is lighter than Radon. Wait, Radon’s atomic mass is ~222, Francium ~223. Maybe Francium? But Francium is alkali metal. Wait, the first clue: “Has the largest atomic mass” — maybe Francium? No, Oganesson is heavier. But maybe the problem refers to natural elements. Let's proceed with standard matches:

• Only alkali metal with no stable isotopes → Francium (Fr)
• Alkaline earth metal with 4 energy levels → Calcium (Ca) (electrons: 2,8,8,2 → 4 levels)
• Most common mass number 131 → Iodine (I)
• Metalloid with smallest mass → Boron (B)
• Only nonmetal in Group 14 → Carbon (C)
• 4 electrons in energy level 5 → Tin (Sn) (Group 14, period 5: n=5, 4 valence electrons)
• 222 is most stable isotope → Radon (Rn)
• Atomic number 81 → Thallium (Tl)
• 84 protons → Polonium (Po)
• Liquid nonmetal → Bromine (Br)
• Liquid metal → Mercury (Hg)
• Member of Group 7 with no stable isotopes → Astatine (At)

If you need to match each left box to the right (missing right boxes, but assuming standard answers), these are the elements for each clue.