Fluorine!
The metal you are referring to is likely calcium. It is in the same period as bromine (period 4) and exhibits similar properties to magnesium due to their shared group (group 2) characteristics, such as reactivity and metallic nature.
Calcium
Sulfur (S) is classified as an active nonmetal in period 4.
Bromine is quite reactive because it is highly electronegative. Electronegativity is a chemical property that measures the ability for an atom to gain electrons from another atom. Thus, the more electronegative an atom is, the more reactive it is. Generally speaking, as you move up a group and across a period on the periodic table, the electronegativity increases. Fluorine has the greatest electronegativity, while francium has the lowest.
Groups go in columns (up and down) and periods go in rows (left to right). Potassium is on the same row as bromine, therefore they are in the same period.
The element that fits this description is chlorine, which is a highly reactive halogen with properties similar to those of magnesium. Chlorine is located in the same period as bromine (Group 17, Period 4) in the periodic table.
The metal you are referring to is likely calcium. It is in the same period as bromine (period 4) and exhibits similar properties to magnesium due to their shared group (group 2) characteristics, such as reactivity and metallic nature.
the metal potassium and the nonmetal bromine
Calcium
Sulfur (S) is classified as an active nonmetal in period 4.
Chlorine (halogen), because Argon is a Nobel gas
Period 5 of the periodic table includes the halogen element bromine (Br). It is a highly reactive nonmetal and exists as a diatomic molecule in its natural state.
Bromine is quite reactive because it is highly electronegative. Electronegativity is a chemical property that measures the ability for an atom to gain electrons from another atom. Thus, the more electronegative an atom is, the more reactive it is. Generally speaking, as you move up a group and across a period on the periodic table, the electronegativity increases. Fluorine has the greatest electronegativity, while francium has the lowest.
In Period 3 of the periodic table, the least reactive metals are found towards the right side, specifically in the group of elements that includes aluminum (Al) and silicon (Si). Among these, aluminum is less reactive compared to sodium (Na) and magnesium (Mg), which are located on the left side of the period. However, metals in Period 3 are generally less reactive than alkali metals and alkaline earth metals found in earlier periods.
A similar element to bromine in the periodic table is iodine. Both bromine and iodine are halogens, located in the same group (Group 17) of the periodic table. They share similar chemical properties due to their valence electron configuration.
The nonmetal in period three with properties similar to iodine is chlorine. Chlorine is in the same group (halogens) as iodine and shares similar chemical properties such as being highly reactive and forming compounds easily.
The period of bromine is the fourth period on the periodic table. It is in the same period as other elements such as potassium, calcium, and argon.