Alkali metal

The video tutorial discusses alkali metals, which are part of Group One in the periodic table. These metals include lithium, sodium, potassium, rubidium, cesium, and francium. They are characterized by being soft, having low density, and reacting easily with air and water to form alkaline compounds. The reactivity of these metals increases with their atomic number, and they are often stored in oil to prevent combustion or corrosion.

Which of the following elements is not an alkali metal?

• Potassium

• Lithium

• Helium

• Sodium

What is a common physical property of alkali metals?

• Softness

• High density

• Non-reactivity

• Hardness

How do alkali metals typically react with water?

• They do not react

• They form alkaline compounds

• They form neutral compounds

• They form acidic compounds

As the atomic number of alkali metals increases, what happens to their reactivity?

• It becomes unpredictable

• It decreases

• It remains the same

• It increases

Why are alkali metals often stored in oil?

• To change their color

• To make them heavier

• To prevent combustion or corrosion

• To enhance their reactivity