Properties and Reactions of Alkali Metals

The video tutorial focuses on alkali metals, which are located in the first column of the periodic table. These metals are characterized by their ability to conduct heat and electricity, softness, low density, and low melting points. The tutorial explains the reactivity trends of alkali metals, highlighting their increasing reactivity down the group. It also covers their reactions with water and air, producing hydroxides and oxides. The video concludes with an explanation of why cesium is more reactive than lithium, emphasizing the role of melting points and surface area in reaction rates.

Which of the following is a characteristic property of alkali metals?

• High density

• Softness

• Non-conductivity

• High melting point

What happens to the atomic radius of alkali metals as you move to the left across the periodic table?

• It fluctuates

• It remains constant

• It increases

• It decreases

Which alkali metal is known to float on water due to its low density?

• Cesium

• Potassium

• Sodium

• Lithium

As you go down the group of alkali metals, what happens to their reactivity?

• It becomes unpredictable

• It remains the same

• It increases

• It decreases

What is the product when sodium reacts with water?

• Sodium carbonate

• Sodium chloride

• Sodium hydroxide

• Sodium oxide

Which compound is formed when sodium reacts with excess oxygen?

• Sodium oxide

• Sodium peroxide

• Sodium superoxide

• Sodium hydroxide

What is the charge of the superoxide ion formed by potassium?

• -1

• +1

• -2

• +2

Why is cesium more reactive than lithium?

• Cesium has a lower melting point

• Cesium is smaller in size

• Cesium has a higher melting point

• Cesium is less electropositive

What happens to the melting point of alkali metals as you go down the group?

• It fluctuates

• It decreases

• It remains constant

• It increases

Which alkali metal has the highest standard reduction potential?

• Potassium

• Sodium

• Lithium

• Cesium