Question

Which metal has a greater tendency to form metal oxide?
A. Cr
B. Fe
C. Al
D. Ca

Answer 1

Hint: Generally, the tendency to form metal oxide decreases across a period and increases down the group. So, we can say that S-Block elements have a greater tendency to form metal oxide.

Complete answer:
- Metal oxides are crystalline solids that contain a metal cation and an oxide anion. It is basically found that they react with water to form bases or react with acids to form salts.
-Generally, the reactivity order of calcium metal is found to be the most reactive because the valence electrons of calcium are far away from the nucleus, that are not held strongly by the nucleus and therefore are easily released. And hence, calcium is found to be most reactive.
- Calcium is a widely used chemical compound. It is a white, alkaline, crystalline solid at room temperature.
- We can say that greater the stability of oxide, greater the ease of its formation. Generally, it is found that ionic oxides are more stable than covalent oxides.
- Now, let’s see how the formation of calcium oxide takes place:
\[2Ca+{{O}_{2}}\to 2CaO\]

- Hence, we can say that option (D) calcium is correct.

Additional information:
There are various Uses of Calcium Oxide found like:
-We can also see that It is used in large scale in the manufacturing of cement, paper, and high-grade steel. It is extensively used for medicinal purposes and insecticides.
- It is found that it is the cheapest alkali available which is an important ingredient in the manufacturing of caustic soda.
- Calcium is essential to human life also, in bones, shells, and teeth. The most common of the calcium compounds is calcium carbonate.

Note:
- We should note that the chemical formula of lime or quicklime is CaO. The chemical name of lime is calcium oxide. On the other hand, the chemical formula of lime water is $Ca{{\left( OH \right)}_{2}}$and the chemical name of this substance is calcium hydroxide. We must not get confused among these terms.