Hydrogen and chlorine.
I assume you mean the "most" reactive to metals, and that would be hydrochloric if I'm not mistaken, might be hydrofluoric.
Magnesium is more reactive with hydrochloric acid compared to copper. When magnesium reacts with hydrochloric acid, it produces hydrogen gas and magnesium chloride, while copper does not readily react with hydrochloric acid.
Lithium is the most reactive.
Magnesium is the most reactive metal with hydrochloric acid because it has a high tendency to lose electrons and form magnesium ions when in contact with the acid. This reaction produces hydrogen gas and magnesium chloride. The high reactivity is due to magnesium's position in the reactivity series of metals and its low ionization energy.
A strong acid solution (hydrochloric acid or sulfuric acid for instance) will dissolve most metals.
Dilute acid should not be added to reactive metals because the result is dangerous. This violent reaction can easily cause damage to property or cause harm to people.
Sulfuric acid and hydrochloric acid are two of the most corrosive acids commonly known. They are highly reactive and can cause severe damage to metals, skin, and other materials upon contact. It's important to handle these acids with care and proper safety precautions.
Most reactive metals are alkali metals, most reactive nonmetalas are halogens.Least reactive metals are platinum metals; least reactive nonmetals are noble gases.
Hydrochloric acid can cause exothermic reactions when mixed with certain reactive metals, which can potentially lead to explosions if the reaction is too vigorous. Additionally, if hydrochloric acid is exposed to heat or flames, it can create explosive hydrogen gas. Proper handling and storage procedures are crucial to prevent accidents.
The Alkali Earth metals are found in group 1 and 2 of the periodic table. When reacted with hydrochloric acid, the vigour of the reactions increases going down the groups. So Lithium will react gently with hydrochloric acid whilst Caesium will react explosively. The same applies for the group 2 metals. Generally speaking, Alkali metals will react with hydrochloric acid: X + HCl -----------> XCl + H2 Where X is the alkali metal and will react to form a chloride
A gas called hydrogen is given off when most metals react with aqueous hydrochloric acid. The ease with which this happens varies: All alkali metals reacts extemely quickly and, with the possible exception of lithium, dangerously. The alkaline earth metals, except beryllium and magnesium, are similar. Most other metals dissolve more slowly and may require heating to evolve the hydrogen gas, and some metals such as copper, gold, and platinum do not react at all.
The most reactive non metals are Halogens which may combine most of the metals as well as non metals.