Alkaline Earth Metals Overview

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the reason beryllium salts exhibit acidity when dissolved in water?

The Be-O bond weakens the O-H bonds, promoting proton loss. (correct)

They release hydroxide ions into the solution.

They form strong ionic bonds with water.

They neutralize bases, creating an acidic environment.

What is the primary structural advantage of beryllium in aerospace applications?

Its high melting point.

Its lightweight and strength. (correct)

Its high thermal conductivity.

Its magnetic properties.

Which alkaline earth metal is known to be used as a reducing agent in the extraction of other metals?

Francium

Calcium (correct)

Radium

Beryllium

Which Group II metal hydroxide is soluble in NaOH?

Be(OH)2 Signup and view all the answers

How many electrons do Group 2 elements have in their S orbital of the valence shell?

2 Signup and view all the answers

Which alkaline earth metal is known for its anomalous behavior?

Beryllium Signup and view all the answers

What is the general trend in atomic radius among the alkaline earth metals?

It increases from beryllium to radium. Signup and view all the answers

Which alkaline earth metal has the highest density?

Radium Signup and view all the answers

How does the ionization energy of alkaline earth metals compare to that of alkali metals?

It is higher. Signup and view all the answers

What distinguishes alkaline earth metals from alkali metals in terms of valence electrons?

They have two valence electrons. Signup and view all the answers

Which of the following is a characteristic of barium?

It has a higher atomic radius than magnesium. Signup and view all the answers

Why are alkaline earth metals considered strong reducing agents?

They readily donate multiple electrons. Signup and view all the answers

What is the effect of the additional charge on the nucleus of alkaline earth metals?

It attracts the orbital electrons more strongly. Signup and view all the answers

What happens to the energy required to remove a second electron from an alkaline earth metal after one electron has been removed?

It nearly doubles compared to the first. Signup and view all the answers

Which characteristic makes the compounds of divalent ions in alkaline earth metals diamagnetic?

Inert gas electron configuration. Signup and view all the answers

How is magnesium commonly extracted from its sources?

By electrolysis of sea water. Signup and view all the answers

What type of reaction do alkaline earth metals undergo with cold water?

They form metal hydroxides and release hydrogen. Signup and view all the answers

Which alkaline earth metal hydroxide is amphoteric and insoluble in water?

Beryllium hydroxide. Signup and view all the answers

Which of the following is true about the oxides formed from alkaline earth metals?

Beryllium oxide is amphoteric. Signup and view all the answers

What method is commonly used for the extraction of calcium from its compounds?

Electrolysis of fused CaCl2 and CaF2. Signup and view all the answers

How does the basic strength of group 2 hydroxides change?

It increases moving down the group. Signup and view all the answers

Which alkaline earth metal hydride is polymeric and covalent?

BeH2 Signup and view all the answers

What distinguishes beryllium from other alkaline earth metals?

Beryllium has a higher electronegativity. Signup and view all the answers

Which chemical property applies to the alkaline earth metals when reacting with halogens?

They form halides in the form MX2. Signup and view all the answers

What is the structural characteristic of beryllium salts in water?

Beryllium salts are extensive hydrolysates. Signup and view all the answers

What type of complex does magnesium form that is essential for plant life?

Chlorophyll Signup and view all the answers

What is a property of beryllium compared to other group II metals?

It is amphoteric. Signup and view all the answers

Which interaction is not true about beryllium compared to aluminium?

Be salts and Al salts both yield acids in hydrolysis. Signup and view all the answers

Which compound does barium produce when it reacts with hydrogen?

BaH2 Signup and view all the answers

Study Notes

Alkaline Earth Metals (Group II)

Group II elements are reactive metals
Located in group 2 of the periodic table
Examples include Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), and Radium (Ra)

General Properties

Size: Atoms are large, but smaller than corresponding Group I elements. Ions are large, but even smaller than corresponding Group I ions due to effective nuclear charge increase after electron removal
Hardness: Hard, higher melting points than Group I metals due to stronger metallic bonding
Ionization Energies: High, with high values required to remove second electrons. The first ionization energy is higher than for Group 1 elements
Reducing Agents: Strong reducing agents, but less than corresponding alkali metals. Calcium is commonly used as a reducing agent in non-aqueous solutions like liquid ammonia.
Colour and Magnetism: Compounds are diamagnetic and colorless due to a complete electron configuration in the ions
Electronic Structure: All have 2 electrons in their outermost s orbital

Anomalous Behaviour of Beryllium

Small size and high electronegativity: Be behaves differently from other Group II elements due to its small size and high effective nuclear charge.
Complex Formation: Forms complexes not typical of other group 2 metals.
Amphoteric Behavior: Be(OH)₂ is amphoteric, meaning it acts as both an acid and a base.
Solubility: Be salts, are highly soluble

Important Compounds and Reactions

Oxides: All react with oxygen to form oxides (MO). Beryllium oxide is amphoteric.
Hydroxides: Hydroxides (M(OH)₂) increase in basicity down the group.
Peroxides: Elements down the group (Sr and Ba) form peroxides (MO₂) more easily.
Reactions with Other Substances: Can react with water, carbon dioxide, hydrogen and with halogens to form metal halides

Extraction of Alkaline Earth Metals

Beryllium (Be): Obtained by electrolysis of molten chlorides, often with added sodium chloride to lower temperature
Magnesium (Mg): Electrolysis of molten MgCl₂ usually obtained from sea water
Other elements (Ca, Sr, Ba): Reduction of corresponding oxides, or electrolysis of their chlorides.

Uses of Alkaline Earth Metals

Beryllium: Used in rockets and spacecraft due to its light weight and strength.
Magnesium: Reducing agent, used in alloys for aircraft bodies
Calcium: Reducing agent, in toothpaste, household detergents, and acid treatment
Barium: Used in diagnostics (Barium sulfate), and as a bleach (Barium peroxide).

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the properties and characteristics of alkaline earth metals in Group II of the periodic table. This quiz delves into their reactivity, atomic size, hardness, ionization energies, and more. Test your knowledge on elements like Beryllium, Magnesium, and Calcium.