Chemistry: Alkali Metals and Covalent Bonding
60 Questions
1 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 is characteristic of a heterogeneous mixture?

  • The particles are of different shapes
  • The particles are dissolved in a solvent
  • The particles are visible to the eye (correct)
  • The particles are of uniform composition

    • What type of bond is characterized by an attraction between ions?

  • Covalent bond
  • Hydrogen bond
  • Metallic bond
  • Ionic bond (correct)

    • What type of electron is not connected to a single atom or covalent bond?

  • Valence electron
  • Delocalised electron (correct)
  • Neutron
  • Free electron

    • What is the main difference between ionic and covalent bonds?

    <p>The presence of electrostatic forces</p> Signup and view all the answers

    What is responsible for the low melting and boiling points of lithium?

    <p>Weak intermolecular forces</p> Signup and view all the answers

    Who discovered the neutron?

    <p>James Chadwick</p> Signup and view all the answers

    What is the ion charge for Alkali metals?

    <p>1</p> Signup and view all the answers

    What determines the number of shells in an atom?

    <p>The period number</p> Signup and view all the answers

    What is the result of an atom losing electrons?

    <p>A positive ion is formed</p> Signup and view all the answers

    What is the term for the electrostatic attraction between positive and negative ions?

    <p>Ionic bonding</p> Signup and view all the answers

    What is the term for an ion made up of a group of atoms?

    <p>Compound ion</p> Signup and view all the answers

    What is the characteristic of ionic substances?

    <p>High melting and boiling points</p> Signup and view all the answers

    What is the result of an atom gaining electrons?

    <p>A negative ion is formed</p> Signup and view all the answers

    What is the effective distance from the center of the nucleus to the outer valence shells?

    <p>Covalent radius</p> Signup and view all the answers

    What is the main reason why alkali metals are stored in oil?

    <p>To keep them away from oxygen in the air</p> Signup and view all the answers

    What is a characteristic of covalent bonds?

    <p>They are strong and have no charge</p> Signup and view all the answers

    What is the difference between an element and a compound?

    <p>An element is a single substance, while a compound is made of two or more elements</p> Signup and view all the answers

    What type of bond is formed between sodium and chlorine in the reaction Na + Cl → NaCl?

    <p>Ionic bond</p> Signup and view all the answers

    What is the main difference between a mixture and a compound?

    <p>A mixture is made of two or more substances physically combined, while a compound is made of two or more elements chemically combined</p> Signup and view all the answers

    What type of bond is formed between the atoms in a simple molecule, such as H2 or Cl2?

    <p>Covalent bond</p> Signup and view all the answers

    What is the main source of energy used to generate electricity in most conventional power stations?

    <p>Coal</p> Signup and view all the answers

    What is the main difference between a series circuit and a parallel circuit?

    <p>The number of paths the current can take</p> Signup and view all the answers

    What is the process of gathering of chemicals in an organism if the rate of intake exceeds the rate of excretion?

    <p>Bioaccumulation</p> Signup and view all the answers

    What is the percentage of energy lost between trophic levels in an energy pyramid?

    <p>90%</p> Signup and view all the answers

    What happens to the resistance when resistors are added in a series circuit?

    <p>It increases</p> Signup and view all the answers

    What is the term for the variety of organisms living in a given area?

    <p>Biodiversity</p> Signup and view all the answers

    What is the unit of measurement for electric current?

    <p>Amps</p> Signup and view all the answers

    What is the role of the turbine in a power station?

    <p>To make the electromagnet spin</p> Signup and view all the answers

    What is the direction of electron flow in an electric circuit?

    <p>From positive to negative</p> Signup and view all the answers

    What is the result of burning coal in a power station?

    <p>Release of carbon dioxide</p> Signup and view all the answers

    What happens to the voltage in a parallel circuit when more resistors are added?

    <p>It remains the same</p> Signup and view all the answers

    What is the purpose of an ammeter in an electric circuit?

    <p>To measure the electric current</p> Signup and view all the answers

    What is the type of energy that is released when coal is burned in a power station?

    <p>Thermal energy</p> Signup and view all the answers

    What is the type of fuel that is formed from the remains of sea creatures?

    <p>Oil and gas</p> Signup and view all the answers

    What is the difference between the current in a series circuit and a parallel circuit?

    <p>The current is different in both circuits</p> Signup and view all the answers

    What is the result of adding more resistors in a parallel circuit?

    <p>The resistance decreases and the current increases</p> Signup and view all the answers

    What is the ion charge for Alkaline earth metals?

    <p>2</p> Signup and view all the answers

    What determines the number of shells in an atom?

    <p>The period number</p> Signup and view all the answers

    What type of ion is formed when an atom loses electrons?

    <p>Cation</p> Signup and view all the answers

    What is the term for the electrostatic attraction between positive and negative ions?

    <p>Ionic bond</p> Signup and view all the answers

    What is the characteristic of ionic substances?

    <p>High melting and boiling points</p> Signup and view all the answers

    What is characteristic of a homogeneous mixture?

    <p>The solute is dissolved in the solvent</p> Signup and view all the answers

    What is the result of an atom gaining electrons?

    <p>Formation of an anion</p> Signup and view all the answers

    What type of force holds atoms together in a metal?

    <p>Metallic bonds</p> Signup and view all the answers

    What is the effective distance from the center of the nucleus to the outer valence shells?

    <p>Covalent radius</p> Signup and view all the answers

    Why does lithium not conduct electricity?

    <p>It has no free ions or electrons</p> Signup and view all the answers

    What is an electron that is not connected to a single atom or covalent bond called?

    <p>Delocalised electron</p> Signup and view all the answers

    What is the term for an ion made up of a group of atoms?

    <p>Compound ion</p> Signup and view all the answers

    What is depicted in a Bohr diagram?

    <p>Electrons orbiting the nucleus</p> Signup and view all the answers

    What type of force is responsible for the attractive and repulsive forces between charged particles?

    <p>Electrostatic forces</p> Signup and view all the answers

    What is the term for the forces of attraction between atoms, molecules, and ions when placed close together?

    <p>Intermolecular forces</p> Signup and view all the answers

    What is the characteristic of a heterogeneous mixture?

    <p>Particles cannot be dissolved and are visible to the eye</p> Signup and view all the answers

    What is the main purpose of reproduction in organisms?

    <p>To provide nutrients and energy to sustain life processes</p> Signup and view all the answers

    What is the characteristic of asexual reproduction?

    <p>Produces genetically identical offspring</p> Signup and view all the answers

    What is the location of the mass of an atom?

    <p>In the nucleus</p> Signup and view all the answers

    What is the purpose of the atomic number?

    <p>To determine the number of protons and electrons</p> Signup and view all the answers

    What is the arrangement of elements in the periodic table?

    <p>In order of increasing atomic number</p> Signup and view all the answers

    What is the significance of energy levels in an atom?

    <p>They determine the arrangement of electrons</p> Signup and view all the answers

    What is the difference between asexual and sexual reproduction?

    <p>Asexual reproduction produces genetically identical offspring, while sexual reproduction produces genetically different offspring</p> Signup and view all the answers

    What is the relationship between the atomic number and the number of electrons?

    <p>The atomic number is equal to the number of protons and electrons</p> Signup and view all the answers

    Study Notes

    Alkali Metals

    • Reactivity of alkali metals increases down the periodic table due to larger atomic size and distance from the nucleus.
    • They must be stored in oil to prevent reaction with oxygen in the air.
    • They react violently with water, releasing enough heat to ignite hydrogen gas.

    Covalent Bonding

    • Covalent bonding involves sharing of atoms.
    • Covalent bonds have no charge.
    • Covalent bonds can be between elements or compounds.
    • Covalent bonds between atoms are strong, but intermolecular forces between molecules are weak.

    Chemical Reactions

    • Sodium reacts with chlorine to form sodium chloride (NaCl).
    • Lithium reacts with iodine to form lithium iodide (LiI).
    • Potassium reacts with bromine to form potassium bromide (KBr).
    • Sodium reacts with water to form sodium hydroxide and hydrogen: Na + H2O → NaOH + H2.

    Elements, Compounds, and Mixtures

    • Elements are the simplest substances that cannot be broken down by chemical means.
    • Compounds are made of two or more elements chemically combined.
    • Mixtures are made of two or more substances physically combined.
    • Heterogeneous mixtures have visible particles, while homogeneous mixtures have dissolved solutes.

    Bonding and Forces

    • Covalent bonds between atoms are strong.
    • Ionic bonds are strong electrostatic forces between ions.
    • Metallic bonds are strong electrostatic forces between metal ions.
    • Intermolecular forces are attractions between atoms, molecules, and ions when close together.

    Conductivity and Electricity

    • Lithium does not conduct electricity because it has no free ions or electrons.
    • Lithium conducts electricity when it has free ions or electrons.

    Atomic Structure and the Periodic Table

    • James Chadwick discovered neutrons.
    • Electrons orbit the nucleus in shells, with principle energy levels indicating the period number.
    • Groups (vertical lines) indicate the number of outer shell electrons.
    • Periods (horizontal lines) indicate the number of shells.

    Ions and Ionic Bonding

    • Ions are atoms or groups of atoms with an electric charge (positive or negative).
    • Atoms with incomplete outer electron shells are unstable.
    • Ion formation occurs when an atom gains or loses electrons, resulting in a charge.
    • Ionic bonding occurs between positively and negatively charged ions.

    Physics

    Series and Parallel Circuits

    • Series circuit: a circuit with only one path for current to flow
    • Parallel circuit: a circuit with at least one branch point where current splits into two or more pathways
    • Current: the flow of electrons, measured in amps (ampere)
    • As you add resistors in a series circuit, resistance increases and current decreases
    • In a parallel circuit, voltage is the same across each component, and resistance decreases as more resistors are added

    Circuits and Components

    • Voltmeter: measures voltage between two points in an electrical circuit
    • Ammeter: measures electric current
    • Resistor: a component that resists the flow of electrons, also known as a component
    • Resistor adjusts the value of current or voltage
    • Cell: stores chemical energy and transfers it to electrical energy when a circuit is connected
    • Battery: two or more cells connected together
    • The bigger the voltage supplied by the cell, the bigger the current

    Ohm's Law

    • Ohm's Law: states that electrical potential difference between two points in a circuit is equal to the current multiplied by the resistance
    • Voltage = Current x Resistance
    • Current = Voltage ÷ Resistance
    • Resistance = Voltage ÷ Current
    • Power = Voltage x Current
    • Resistance is the limit of flow of charge
    • The bigger the resistance, the less the current will flow
    • Power is the amount of energy consumed or released by a circuit

    Fossil Fuels

    Coal

    • Coal: a fossil fuel formed from the remains of plants
    • Thermal energy: the energy contained within a system that is responsible for its temperature (heat)
    • Steps involved in generating electricity from coal:
      1. Coal is shipped and transported near the power station
      2. Coal is moved to the power station by conveyor belts
      3. Coal is ground into a fine powder (pulverised)
      4. Pulverised coal is transported into the furnace
      5. Coal is burned inside the furnace, releasing heat energy
      6. Heat energy is used to turn water into steam
      7. Steam makes the turbine spin
      8. Turbine makes the electromagnet spin
      9. Electromagnet generates electricity
      10. Electricity is sent to homes through the national grid

    Problems with Using Coal as an Energy Source

    • Carbon dioxide is released, causing global warming
    • Sulphur and nitrogen oxides are released, causing acid rain
    • Dust from mining causes smog (air pollution that reduces visibility)
    • Destruction of landscape and habitats
    • Coal is a non-renewable energy source, eventually running out

    Ecology

    Energy Levels

    • Food chains can be organised into an energy pyramid
    • Trophic levels: 1 (producers), 2 (primary consumers), 3 (secondary consumers), 4 (tertiary consumers)
    • 90% of energy is lost between trophic levels
    • Energy is lost as heat or undigested

    Food Web

    • Food web: made up of multiple food chains that interact together
    • Shows more interactions among producers and consumers
    • Shows biodiversity (all types of organisms living in a given area)
    • Biodiversity contributes to the sustainability of an ecosystem

    Bioaccumulation

    • Bioaccumulation: the process of gathering chemicals in an organism if the rate of intake exceeds the rate of excretion
    • As the human population grows, more waste is produced, leading to bioaccumulation

    Chemistry

    Atoms

    • Atom: has a neutral charge, with a nucleus and electrons
    • Protons and electrons have the same amount, and the mass number is the number of protons and neutrons added together
    • Electrons orbit the nucleus at set distances in certain fixed energy levels (shells)
    • The atomic number tells you how much electrons and protons there are

    Periodic Table

    • The chemical elements are arranged in order of increasing atomic number
    • Horizontal rows are called periods, and vertical columns are called groups
    • Ion charges are indicated by +(number)

    Ions and Ionic Bonding

    • Ion: an atom or group of atoms with an electric charge, either positive or negative
    • Cations: positive ions, formed when an atom loses electrons
    • Anions: negative ions, formed when an atom gains electrons
    • Ionic bonding: the electrostatic attraction between oppositely charged ions
    • Ionic substances form giant ionic lattices containing oppositely charged ions, with high melting and boiling points

    Studying That Suits You

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

    Quiz Team

    Related Documents

    grade 9 Finals review.docx

    Description

    Learn about the properties of alkali metals, including their reactivity and storage requirements, and the basics of covalent bonding in chemistry.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser