Calcium and Its Properties

The video tutorial explores the properties of calcium, a metal that becomes harder down the group and is coated with metal oxide. It conducts electricity and reacts rapidly with water due to its low ionization energy, producing hydrogen gas and calcium hydroxide. The reaction is exothermic. Tests for hydrogen gas and calcium hydroxide are demonstrated using flammability and phenolphthalein indicator, respectively, to confirm the presence of these products.

What happens to metals as you move down the group in the periodic table?

• They become softer.

• They become more brittle.

• They become less conductive.

• They become harder.

Why is calcium coated with a layer of metal oxide?

• To enhance its conductivity.

• Because it is stored in air.

• To make it more malleable.

• To prevent it from reacting with water.

What type of reaction occurs when calcium is added to water?

• Synthesis reaction

• Single displacement reaction

• Decomposition reaction

• Double displacement reaction

What is produced when calcium reacts with water?

• Nitrogen gas and calcium nitride

• Carbon dioxide and calcium carbonate

• Hydrogen gas and calcium hydroxide

• Oxygen gas and calcium oxide

How can you test for the presence of hydrogen gas?

• By measuring its density

• By checking its flammability

• By using a litmus test

• By observing its color

What indicates the formation of calcium hydroxide in a solution?

• The solution turns purple with phenolphthalein

• The solution turns red

• The solution becomes acidic

• The solution becomes neutral