Solution. Calcium reacts with oxygen to form calcium oxide with a high melting point. This compound is also soluble in water.

The reaction between oxygen and another element generally results in the formation of a binary compound known as an oxide. The reaction itself is known as oxidation. For example, the oxidation reaction between oxygen and sodium produces sodium oxide. Oxygen also reacts with a number of compounds.

D. Iron. Hint: The answer of this problem is a metal and the compound formed when this metal reacts with oxygen has a high melting point because it is ionic in nature. So, the element belongs to either group I or II which form ionic compounds.

Ionic compounds are held together by electrostatic forces between the oppositely charged ions . As the ionic lattice contains such a large number of ions, a lot of energy is needed to overcome this ionic bonding so ionic compounds have high melting and boiling points.

Alkali Metals

Most alkali metals and alkaline earth metals react with water to produce hydrogen. The alkali metals comprise Group 1 of the periodic table, and include lithium, sodium, potassium, rubidium, cesium and francium.

The oxides of high reactive metals are very stable and cannot be reduced by carbon . Because metals have more affinity towards oxygen than carbon.so carbon is unable to remove oxygen from these metals oxides and convert them into free metals. Explanation: Hope this answer helps you.

Sodium metal reacts rapidly with water to form a colourless solution of sodium hydroxide (NaOH) and hydrogen gas (H2). The resulting solution is basic because of the dissolved hydroxide. During the reaction, the sodium metal may well become so hot that it catches fire and burns with a characteristic orange colour.

Sodium is stored in kerosene as it is a highly reactive metal. If it is kept in open air, it easily reacts with the oxygen and catches fire. Since kerosene is a mixture of hydrocarbons, it won’t react with it….Thank you.

Phosphorus is found in three main forms: white, red, and black. White phosphorus is highly reactive, and spontaneously ignites at about 30°C in moist air. It is usually stored under water, to prevent exposure to the air. It is also extremely toxic, even in very small quantities.