Group 2 - Alkaline Earth Metals | Properties of Matter | Chemistry | FuseSchool

Summary

In this lesson, we explore the alkaline earth metals in Group 2 of the periodic table, focusing on magnesium and calcium. These metals have similar properties, such as the ability to lose two valence electrons and form positive ions. We examine their reactions with oxygen and water, where magnesium forms magnesium oxide upon burning, and calcium forms calcium oxide. Magnesium reacts with steam, while calcium reacts with cold water, producing hydrogen gas and calcium hydroxide. The lesson highlights the increasing reactivity of these metals as you move down the group.

Takeaways

• 😀 The alkaline earth metals are located in Group 2 of the periodic table and include magnesium, calcium, strontium, barium, and radium.
• 😀 These metals all have two electrons in their valence shell and can lose them to form ions with a +2 charge.
• 😀 Except for magnesium, alkaline earth metals are stored in oil to prevent reaction with air, as they are reactive with oxygen and water.
• 😀 Moving down Group 2, the metals become softer, their density and reactivity increase, while their melting and boiling points decrease.
• 😀 Magnesium reacts with oxygen to form magnesium oxide, which is a white solid, but it has an oxide layer that must be cleaned before use.
• 😀 When magnesium is heated in a Bunsen burner flame, it burns with a bright white flash, so it's important not to look directly at the flame.
• 😀 Calcium is softer than magnesium and reacts with oxygen to form calcium oxide, which is also a white solid.
• 😀 Calcium oxide reacts with water to form calcium hydroxide (lime water), producing a white precipitate at the bottom of the beaker.
• 😀 Magnesium reacts with steam (not cold water) to form magnesium oxide and hydrogen gas.
• 😀 Calcium reacts more vigorously with cold water than magnesium, producing calcium hydroxide and hydrogen gas, with effervescence indicating gas release.
• 😀 The alkaline earth metals exhibit similar reactivity trends to alkali metals, with increasing reactivity and decreasing hardness as you move down the group.

Q & A

What group of the periodic table do alkaline earth metals belong to?

Alkaline earth metals belong to Group 2 of the periodic table.

What are the key elements in the alkaline earth metals group that were discussed in the lesson?

The key elements discussed are magnesium and calcium.

What property do all alkaline earth metals share in terms of their electron configuration?

All alkaline earth metals have two electrons in their valence shell.

Why is magnesium often found with a dull appearance despite being shiny and silver?

Magnesium often appears dull due to the formation of an oxide layer when exposed to air.

How does magnesium react with oxygen?

Magnesium reacts with oxygen to produce magnesium oxide, a white solid, and the reaction produces a bright white flash.

What happens when calcium reacts with oxygen?

Calcium reacts with oxygen to form calcium oxide, which is also a white solid.

Which is softer: magnesium or calcium?

Calcium is softer than magnesium.

What is the reaction of calcium oxide when placed in cold water?

Calcium oxide reacts with cold water to form calcium hydroxide, also known as lime water, and a white precipitate forms at the bottom of the beaker.

What is the key difference in how magnesium and calcium react with water?

Magnesium reacts only with steam to produce magnesium oxide and hydrogen gas, while calcium reacts more vigorously with cold water to produce calcium hydroxide and hydrogen gas.

What happens when hydrogen gas is produced in the reaction of calcium with water?

Hydrogen gas is produced as effervescence, and calcium sinks to the bottom of the container.