Group 2A (or IIA) of the periodic table are the alkaline earth metals: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). They are harder and less reactive than the alkali metals of Group 1A.

Strontium and barium will also react with oxygen to form strontium or barium peroxide. Strontium forms this if it is heated in oxygen under high pressures, but barium forms barium peroxide just on normal heating in oxygen.

However, the reaction is short-lived because the magnesium hydroxide formed is almost insoluble in water and forms a barrier on the magnesium preventing further reaction. As a general rule, if a metal reacts with cold water, the metal hydroxide is produced. If it reacts with steam, the metal oxide is formed.

Like other alkaline-earth metals, strontium is highly reactive chemically and reacts with both air and water. When exposed to air, it burns with a bright red flame. When combined with water, strontium gives off hydrogen gas and strontium hydroxide — a strong irritant.

In what way and in what form does strontium react with water? Strontium reacts with water slowly, generally to strontium hydroxide and hydrogen gas. It reacts with water quicker than calcium, which is placed directly above strontium in the periodic chart, and slower than barium, placed directly below strontium.

When the magnesium metal burns it reacts with oxygen found in the air to form Magnesium Oxide. A compound is a material in which atoms of different elements are bonded to one another. Oxygen and magnesium combine in a chemical reaction to form this compound.

Adding magnesium metal to hydrochloric acid produces hydrogen gas. The magnesium dissolves to form magnesium chloride, MgCl2. Let’s write a balanced equation for this reaction.

When magnesium ribbon reacts with hydrochloric acid, magnesium chloride will be formed and hydrogen gas is liberated. There will be a change in temperature of the test tube, slight fizzing of gas bubbles,then the magnesium ribbon will dissolve into water, leaving in blue.

magnesium nitrate

Magnesium is a highly flammable metal, but while it is easy to ignite when powdered or shaved into thin strips, it is difficult to ignite in mass or bulk. Once ignited it is difficult to extinguish, being able to burn in both nitrogen (forming magnesium nitride), and carbon dioxide (forming magnesium oxide and carbon).

He also notes that ice makes magnesium burn hotter. Water is among the compounds that reacts with magnesium when it burns, increasing the reaction and turning magnesium and water into hydrogen and magnesium oxide.

It is true that magnesium alloys are highly combustible when in a finely divided form, such as powder or fine chips, and this hazard should never be ignored. Above 800 °F (427 °C), a non-combustible, oxygen-free atmosphere is required to suppress burning.

Reaction of magnesium with water This is in contrast with calcium, immediately below magnesium in the periodic table, which does react slowly with cold water. Magnesium metal does however react with steam to give magnesium oxide (MgO) (or magnesium hydroxide, Mg(OH)2, with excess steam) and hydrogen gas (H2).