Group 2 Elements: Atomic Radius & Ionization Energy
22 Questions
2 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What trend is observed in the atomic radius as one moves down Group 2 of the periodic table?

  • Atomic radius decreases.
  • Atomic radius first increases, then decreases.
  • Atomic radius remains constant.
  • Atomic radius increases. (correct)

    • Why does the first ionization energy decrease as one moves down Group 2?

  • Increased shielding outweighs the nuclear charge. (correct)
  • Outer electrons are closer to the nucleus.
  • Increased nuclear charge dominates.
  • Electrons gain more energy at lower levels.

    • How do Group 2 elements generally react with water as one moves down the group?

  • Reactivity is constant with all elements.
  • Reactivity decreases.
  • Reactivity increases. (correct)
  • Reactivity remains unchanged.

    • What type of flame is produced when magnesium reacts with oxygen?

    <p>Bright white flame. (A)</p> Signup and view all the answers

    What is the solubility trend for Group 2 hydroxides as you move down the group?

    <p>Solubility increases. (C)</p> Signup and view all the answers

    What is produced when Group 2 carbonates decompose upon heating?

    <p>Metal oxides and carbon dioxide. (A)</p> Signup and view all the answers

    What is the impact of charge density of the metal ion on the stability of carbonates and nitrates?

    <p>Higher charge density increases stability. (D)</p> Signup and view all the answers

    Which compound is sparingly soluble among the Group 2 sulfates?

    <p>Barium sulfate. (D)</p> Signup and view all the answers

    What is the primary reason for the decreasing stability of carbonate and nitrate ions?

    <p>Increased charge density leads to greater distortion. (B)</p> Signup and view all the answers

    Which color flame is produced by lithium during a flame test?

    <p>Crimson (D)</p> Signup and view all the answers

    What trend is observed in the reactivity of halogens as we move down Group 7?

    <p>Reactivity decreases. (A)</p> Signup and view all the answers

    When chlorine displaces bromide ions from a bromide solution, what color is observed in the organic layer?

    <p>Orange organic layer and yellow aqueous layer (A)</p> Signup and view all the answers

    What happens to the boiling points of halogens as you move down the group?

    <p>Boiling points increase. (D)</p> Signup and view all the answers

    In the disproportionation reaction of bromine with cold sodium hydroxide, what products are formed?

    <p>Sodium bromide and sodium bromate(I) (C)</p> Signup and view all the answers

    What is bleach primarily composed of?

    <p>Sodium chlorate(I) (D)</p> Signup and view all the answers

    As halogens descend in Group 7, how does their oxidizing power change?

    <p>It decreases. (D)</p> Signup and view all the answers

    What do iodide ions produce when they react with sulfuric acid?

    <p>Sulfur dioxide and hydrogen sulfide (B)</p> Signup and view all the answers

    What color precipitate does chloride ions form when reacted with silver nitrate?

    <p>White precipitate (C)</p> Signup and view all the answers

    Which ion can liberate ammonia gas upon heating with sodium hydroxide?

    <p>Ammonium ion (D)</p> Signup and view all the answers

    What is observed when a carbonate reacts with acid?

    <p>Bubbling through limewater and cloudy precipitation (B)</p> Signup and view all the answers

    Which halogen can only form oxidation states of 0 or -1?

    <p>Fluorine (C)</p> Signup and view all the answers

    What happens to the reducing power of halide ions as they move down the group?

    <p>It increases. (B)</p> Signup and view all the answers

    Flashcards

    Atomic Radius

    The distance from the nucleus to the outermost electron shell, increases down Group 2.

    Ionization Energy

    Energy required to remove an outer electron. Decreases down Group 2.

    Reactivity with Water

    Group 2 elements form metal hydroxides when reacting with water, more reactive down the group.

    Solubility of Hydroxides

    Solubility increases down Group 2 for hydroxides but decreases for sulfates.

    Signup and view all the flashcards

    Thermal Decomposition of Carbonates

    Heating Group 2 carbonates produces metal oxides and carbon dioxide.

    Signup and view all the flashcards

    Stability of Nitrates

    Metal ion charge density affects the stability of nitrates and carbonates.

    Signup and view all the flashcards

    Metal Oxides Formation

    Group 2 elements react with oxygen to produce metal oxides.

    Signup and view all the flashcards

    Shielding Effect

    Inner electron shells shield outer electrons from nucleus, decreasing ionization energy.

    Signup and view all the flashcards

    Charge Density

    The amount of charge per unit volume in an ion; higher means more distortion in electron clouds.

    Signup and view all the flashcards

    Flame Tests

    A method to identify cations by the color produced when heated.

    Signup and view all the flashcards

    Bunsen Flame

    A blue flame used in flame tests to produce distinct colors.

    Signup and view all the flashcards

    Halogens

    Elements in Group 7 of the periodic table; known for high reactivity.

    Signup and view all the flashcards

    Displacement Reaction

    A more reactive halogen replaces a less reactive halogen from its solution.

    Signup and view all the flashcards

    Boiling Points of Halogens

    Boiling point increases down the group due to larger atomic size.

    Signup and view all the flashcards

    Oxidation States of Halogens

    Halogens can have multiple oxidation states, with varied reactivity.

    Signup and view all the flashcards

    Disproportionation Reaction

    A reaction where an element is both oxidized and reduced.

    Signup and view all the flashcards

    Bleach

    Sodium chlorate(I) solution used as a disinfectant and cleaner.

    Signup and view all the flashcards

    Reducing Power of Halide Ions

    Halide ions lose electrons; power increases down the group.

    Signup and view all the flashcards

    Reactions with Silver Nitrate

    Halide ions produce colored precipitates with silver nitrate.

    Signup and view all the flashcards

    Carbonate Test

    Reaction of carbonates with acid produces CO2, tested with limewater.

    Signup and view all the flashcards

    Sulfate Test

    Barium chloride reacts with sulfates to form a white precipitate.

    Signup and view all the flashcards

    Halogen Reactivity Trend

    Reactivity of halogens decreases down the group.

    Signup and view all the flashcards

    Ammonium Compounds Test

    Ammonium compounds release ammonia gas when heated with NaOH.

    Signup and view all the flashcards

    Study Notes

    Atomic Radius & Ionization Energy

    • Atomic radius increases as we move down Group 2 of the periodic table due to the addition of electron shells.
    • First ionization energy decreases down Group 2 because increased shielding from extra electron shells outweighs the increasing nuclear charge.
    • This shielding effect weakens the attraction between the nucleus and the outermost electron, making it easier to remove.

    Reactions of Group 2 Elements

    • Group 2 elements react with water to form metal hydroxides (bases).
    • Reactivity with water increases down the group due to increasing atomic radius and shielding.
    • Magnesium reacts slowly with water; more vigorous reaction with steam produces magnesium oxide instead of hydroxide.
    • Group 2 elements react with oxygen to form metal oxides (bases).
    • The reaction produces a bright white flame (e.g., magnesium burns with a white flame).
    • Group 2 elements react with chlorine to form metal chlorides.

    Solubility of Group 2 Compounds

    • Group 2 hydroxides and sulfates exhibit opposite solubility trends down the group.
    • Solubility of sulfates decreases with increasing atomic number (e.g., magnesium sulfate is soluble, barium sulfate is sparingly soluble; double-charged anion).
    • Solubility of hydroxides increases with increasing atomic number (e.g., magnesium hydroxide is sparingly soluble, barium hydroxide is soluble; single-charged anion).

    Thermal Decomposition of Group 2 and Group 1 Compounds

    • Group 2 carbonates and nitrates decompose on heating to form metal oxides, carbon dioxide, and/or nitrogen dioxide.
    • Group 2 carbonates decompose to metal oxides and carbon dioxide.
    • Group 2 nitrates decompose to metal oxides, nitrogen dioxide, and oxygen.
    • Group 1 carbonates are generally thermally stable but lithium carbonate decomposes to lithium oxide and carbon dioxide.
    • Group 1 nitrates decompose to nitrites and oxygen, except for lithium nitrate which forms lithium oxide, nitrogen dioxide, and oxygen.

    Stability of Carbonates and Nitrates

    • Carbonate and nitrate stability depend on metal ion charge density.
    • Higher charge density causes greater distortion of electron clouds, reducing stability.
    • Larger metal ions have lower charge density, leading to less distortion and increased stability.

    Flame Tests

    • Flame tests identify cations by observing colors produced when a sample is heated in a blue Bunsen flame.
    • Colors are due to electron transitions between energy levels, releasing light of varying wavelengths.
    • The nichrome wire is cleaned with concentrated hydrochloric acid before use.
    • Specific cations produce characteristic colors: lithium (crimson), sodium (yellowy orange), potassium (lilac), rubidium (red), cesium (blue), calcium (dark red), strontium (crimson), barium (green).

    Halogens

    • Halogens are Group 7 elements.
    • Reactivity decreases down the group.
    • Oxidizing power decreases down the group.
    • Boiling points increase down the group due to increasing London Dispersion forces.
    • Physical state changes from gas (fluorine) to solid (iodine) due to increasing boiling point.

    Displacement Reactions of Halogens

    • More reactive halogens displace less reactive halogens from their halide solutions.
    • The organic layer's color reveals the displaced halogen.
    • Example: Chlorine displaces bromide, creating a yellow aqueous layer and orange organic layer.

    Reactions of Halogens with Group 1 and 2 Elements

    • Halogens react with Group 1 and 2 elements to form metal halides.
    • These reactions involve metal oxidation and halogen reduction.

    Oxidation States of Halogens

    • Halogens exhibit various oxidation states.
    • Fluorine has oxidation states of 0 and -1.
    • Other halogens (e.g., chlorine, bromine, iodine) can have both positive and negative oxidation states.
    • Roman numerals in names (e.g., bromate(III)) indicate the halogen's oxidation state.

    Disproportionation Reactions of Halogens

    • Halogens disproportionate in cold alkali solutions, oxidizing to +1 and reducing to -1.
    • Example: Bromine with sodium hydroxide produces sodium bromide and sodium bromate(I).
    • Hot alkali solutions cause disproportionation to +5 and -1.
    • Example: Chlorine with sodium hydroxide produces sodium chloride and sodium chlorate(V).

    Bleach

    • Bleach is a sodium chlorate(I) solution from chlorine disproportionation in sodium hydroxide.
    • It disinfects, cleans, and bleaches due to its oxidizing power.

    Oxidizing Power of Halogens

    • Halogens gain electrons and act as oxidizing agents.
    • Oxidizing power decreases down the group due to weaker nucleus-outer electron attraction.

    Reducing Power of Halide Ions

    • Halide ions lose electrons and act as reducing agents.
    • Reducing power increases down the group due to greater nuclear distance from outermost electrons.

    Reactions of Halide Ions with Sulfuric Acid

    • Halide ion reactions with sulfuric acid depend on the halide and conditions.
    • Chlorides do not react.
    • Bromides produce sulfur dioxide.
    • Iodides produce sulfur dioxide, sulfur, and hydrogen sulfide.

    Reactions of Halide Ions with Silver Nitrate

    • Halide ions form silver halide precipitates with silver nitrate.
    • Chloride produces white silver chloride.
    • Bromide gives cream silver bromide.
    • Iodide results in yellow silver iodide.
    • Dilute ammonia dissolves silver chloride; concentrated ammonia dissolves silver bromide, but not iodide.

    Tests for Specific Ions

    • Carbonates react with acid to produce carbon dioxide (tested by limewater cloudiness).
    • Sulfates give a white barium sulfate precipitate with barium chloride.
    • Ammonium compounds release ammonia gas (pungent smell, turns red litmus blue) when heated with sodium hydroxide.
    • Hydroxides are alkaline; turn red litmus blue.

    Conclusion

    • Comprehensive overview of Group 2 and 7 elements and their properties, reactions, and trends.
    • Highlights periodic table trends (atomic radius, ionization energy, reactivity).
    • Discusses practical applications (bleach, flame tests).

    Studying That Suits You

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

    Quiz Team

    Description

    Explore the properties of Group 2 elements, focusing on atomic radius and ionization energy. Learn how these properties change as you move down the group, affecting reactivity with water and oxygen. This quiz will deepen your understanding of these important trends in the periodic table.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser