Presumably francium -- I don't know whether enough has ever been made to test. Among stable elements, cesium.
Hydrogen...
Lithium is NOT the most active alkali metal. Francium is the most active but is available in such trace quantities and radioactive that for practical purposes it is Cesium that is considered most active.
fluorine
No, calcium (Ca) is not the most active element. The most active elements are typically found in Group 1 of the periodic table, such as sodium (Na) and potassium (K), which readily react with water and air.
No. Au (gold) is one of the least active elements.
Hydrogen...
Carbon, if not wiki it
That is not true. The first element in a period may be active or inactive, depending on the specific electron configuration of the element. For example, the first element in period 1, hydrogen, is not considered an active element.
No. Be is active, but is nowhere near the most active element.
This is chlorine.
Potassium is the most active metal. It is highly reactive and can easily react with water to produce hydrogen gas and caustic potassium hydroxide.
No. while magnesium is a very active element is is far from being the most active.
Fluorine is sometimes called the hungry wolf of the periodic table because it is the most reactive element.
Fr or Francium is the most reactive alkali metal (group 1)
This element is sodium (Na).
Fluorine is the most active non-metal due to its high electronegativity, which allows it to readily gain an electron to achieve a stable electron configuration. Francium is the most active metal because it has the lowest ionization energy among all the elements, making it highly reactive and prone to losing an electron to form a positive ion.
Lithium is NOT the most active alkali metal. Francium is the most active but is available in such trace quantities and radioactive that for practical purposes it is Cesium that is considered most active.