Structure of the Atom (Physics Chap. 2)
62 Questions
3 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

Who is credited with expanding on and formalizing the earliest atomic theory?

  • Leucippus
  • A Greek philosopher
  • John Dalton
  • Democritus of Abdera (correct)

    • What is the meaning of the Greek word 'atomos'?

  • Indivisible (correct)
  • Element
  • Compound
  • Divisible

    • According to Democritus, what determines the nature of an object?

  • The atoms it is composed of (correct)
  • The shape of its atoms
  • The structure of its atoms
  • The size of its atoms

    • Who developed a sound atomic theory based on scientific evidence in the early 1800s?

    <p>John Dalton</p> Signup and view all the answers

    What led to John Dalton's development of his atomic theory?

    <p>The recognition of elements combining in definite proportions</p> Signup and view all the answers

    What is a characteristic of Democritus' atoms?

    <p>They are indestructible</p> Signup and view all the answers

    What was the main idea of Dalton's atomic theory?

    <p>Compounds are formed by molecules and molecules by fixed ratios of each type of constituent atom</p> Signup and view all the answers

    What was the significance of Mendeleev's work?

    <p>He organized the known elements into the periodic table</p> Signup and view all the answers

    What was J.J. Thomson's discovery?

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

    What was the 'plum pudding model' of the atom?

    <p>A positively charged sphere with negatively charged electrons embedded in it</p> Signup and view all the answers

    What was Rutherford's discovery?

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

    What is the current understanding of the atom?

    <p>The atom is made up of electrons, protons, and neutrons</p> Signup and view all the answers

    What is the significance of Niels Bohr's work?

    <p>He refined Rutherford's model of the atom</p> Signup and view all the answers

    What are the three fundamental components of the atom?

    <p>Electrons, neutrons, and protons</p> Signup and view all the answers

    What is the purpose of selecting elements in radiology?

    <p>Because of their atomic structure and how they interact with x-rays</p> Signup and view all the answers

    What was Rutherford's experiment that led to his discovery?

    <p>Bombarding a thin sheet of gold with alpha particles</p> Signup and view all the answers

    What is the primary difference between protons and neutrons?

    <p>Protons have a positive electrical charge.</p> Signup and view all the answers

    What is the composition of the nucleus?

    <p>Protons and neutrons (nucleons)</p> Signup and view all the answers

    What is the charge of an atom with an equal number of protons and electrons?

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

    What is the result when an atom gains an extra electron?

    <p>The atom becomes a negative ion</p> Signup and view all the answers

    What is the binding energy in the nucleus?

    <p>The energy that holds the protons and neutrons together</p> Signup and view all the answers

    What is the mass defect?

    <p>The difference between the nuclear mass and the sum of the individual nucleon masses</p> Signup and view all the answers

    What is the purpose of the binding energy?

    <p>To hold the protons and neutrons together</p> Signup and view all the answers

    What is the charge of an electron?

    <p>One unit of negative charge</p> Signup and view all the answers

    What is the result when an atom loses an electron?

    <p>The atom becomes a positive ion</p> Signup and view all the answers

    What is the significance of the statement 'like charges repel each other, opposites attract'?

    <p>It is a law of electrostatics</p> Signup and view all the answers

    What is the unit of measurement for nuclear binding energy?

    <p>Megaelectron-volts (MeV)</p> Signup and view all the answers

    What determines the penetrating strength of x-ray photons produced through characteristic interactions?

    <p>Electron-binding energies of the electron shells involved</p> Signup and view all the answers

    What is the maximum number of electrons that can occupy the first electron shell (K shell)?

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

    What is the formula to determine the maximum number of electrons that can fit in an electron shell?

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

    What is the term for the energy that holds electrons in their orbits around the nucleus?

    <p>Electron-binding energy</p> Signup and view all the answers

    What is the order of electron shells, starting from the nucleus?

    <p>K, L, M, N, O, P</p> Signup and view all the answers

    What is the term for the energy that holds protons and neutrons together in the nucleus?

    <p>Nuclear binding energy</p> Signup and view all the answers

    What determines the penetrating strength of x-ray photons produced through bremsstrahlung interactions?

    <p>Nuclear binding energy</p> Signup and view all the answers

    What is the maximum number of electrons that can occupy the outermost shell of any atom?

    <p>8</p> Signup and view all the answers

    What is the shape of the electron orbit around the nucleus?

    <p>Three-dimensional</p> Signup and view all the answers

    What is a characteristic of larger atoms that makes them more likely to interact with x-ray photons?

    <p>They have more electron shells and electrons</p> Signup and view all the answers

    What is the primary difference between atomic number and atomic mass number?

    <p>Atomic number is the number of protons, while atomic mass number is the number of protons and neutrons</p> Signup and view all the answers

    What is the term for the simplest forms of substances that compose matter?

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

    What is the purpose of the superscript number in chemical shorthand?

    <p>It represents the atomic mass number</p> Signup and view all the answers

    What is an isotope of an element?

    <p>An element with the same number of protons but a different number of neutrons</p> Signup and view all the answers

    What is the primary difference between an isomer and an isotope of an element?

    <p>The arrangement of protons and neutrons in the nucleus</p> Signup and view all the answers

    How do the number of electron shells and electrons in an atom affect its interactions with x-ray photons?

    <p>The more electron shells and electrons, the greater the opportunity for interactions</p> Signup and view all the answers

    What is the term for two or more atoms bonded together?

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

    Why are larger atoms more likely to interact with x-ray photons than smaller atoms?

    <p>Because they have a larger nucleus and more electron shells</p> Signup and view all the answers

    What is the term for elements whose atoms have the same number of protons but a different number of neutrons?

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

    What is the characteristic that stays the same in isotopes?

    <p>Number of protons</p> Signup and view all the answers

    What is the characteristic that stays the same in isobars?

    <p>Atomic mass number</p> Signup and view all the answers

    What determines the grouping of elements in the periodic table?

    <p>Atomic number</p> Signup and view all the answers

    What is unique about the elements in the middle of the periodic table?

    <p>They are the transitional metals</p> Signup and view all the answers

    What is the characteristic of a molecule?

    <p>It is formed by two or more atoms bonded together</p> Signup and view all the answers

    What is the difference between a molecule and a compound?

    <p>A compound is a type of molecule</p> Signup and view all the answers

    What is the basis of ionic bonding?

    <p>Attraction of opposing charges</p> Signup and view all the answers

    What occurs when an atom gains an electron?

    <p>It becomes an anion</p> Signup and view all the answers

    What is the term for an atom that gives up an electron?

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

    What is the purpose of the periodic table?

    <p>To show the characteristics of elements</p> Signup and view all the answers

    What occurs when an atom gives up an electron in an ionic bond?

    <p>It becomes positively charged</p> Signup and view all the answers

    What is the main difference between ionic and covalent bonds?

    <p>The way electrons are shared</p> Signup and view all the answers

    What is the purpose of the strong nuclear force?

    <p>To bind protons and neutrons together</p> Signup and view all the answers

    What is the result when two atoms share electrons in a covalent bond?

    <p>The outermost shells of both atoms are completed</p> Signup and view all the answers

    What is the reason for the electrostatic attraction between the nucleus and electrons?

    <p>Opposite charges attract each other</p> Signup and view all the answers

    What is the term for the classification of elements based on the number of protons, neutrons, and electrons?

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

    Study Notes

    Atomic Theory

    • The concept of atomic theory dates back to ancient Greece, with Leucippus and Democritus being prominent contributors.
    • Democritus hypothesized that all things are made up of tiny, indivisible structures called atoms, which vary in size, shape, and structure.
    • He believed that the nature of an object depends on its atoms, with smooth atoms making up sweet things and sharp atoms making up bitter things.

    Development of Atomic Theory

    • In the early 1800s, John Dalton developed a sound atomic theory based on scientific evidence, proposing that:
      • Elements are composed of tiny, indivisible, and indestructible particles called atoms.
      • Atoms are unique to each element in their size and mass.
      • Compounds are formed by molecules, which are made up of fixed ratios of each type of constituent atom.
      • Chemical reactions involve the rearrangement of atoms.
    • Later, Dmitri Mendeleev organized the known elements into the periodic table, which demonstrates that elements have similar chemical properties when arranged in order of increasing atomic mass.

    Subatomic Particles

    • Joseph John Thomson discovered the electron, which is a negatively charged particle that orbits the nucleus of an atom.
    • The plum pudding model describes the atom as a positively charged sphere with negatively charged electrons embedded in it.
    • Ernest Rutherford's experiments led to the development of the nuclear model, which proposes that:
      • The atom has a dense, positively charged nucleus at its center.
      • Electrons orbit the nucleus in defined paths.

    Atomic Structure

    • The atom is composed of three fundamental particles: protons, neutrons, and electrons.
    • The nucleus is made up of protons and neutrons, which are collectively called nucleons.
    • Protons have a positive electrical charge, neutrons have no charge, and electrons have a negative electrical charge.
    • The atomic mass of an atom is the sum of the masses of its protons and neutrons.

    Atomic Charge

    • The electrical charge of an atom is determined by the number of protons and electrons it has.
    • If an atom has an equal number of protons and electrons, it has no net charge.
    • If an atom gains or loses electrons, it becomes positively or negatively charged, respectively.

    Electron Orbits

    • Electrons occupy specific energy levels, or electron shells, which are at different distances from the nucleus.
    • Each electron shell has a maximum number of electrons it can hold, which is determined by the formula 2n^2.
    • The outermost shells of atoms may not be fully occupied, and the number of electrons in the outermost shell can vary.

    Binding Energy

    • Binding energy is the energy required to hold the nucleus together.
    • Electron-binding energy is the energy required to hold an electron in its orbit.
    • The binding energy of an atom determines its ability to interact with other atoms and particles.

    Classification and Bonding

    • Elements are classified based on the number of protons, neutrons, and electrons in their atoms.

    • Isotopes, isotones, isobars, and isomers are classifications of elements based on the number of protons, neutrons, and electrons in their atoms.

    • The periodic table is a way of organizing elements based on their atomic number and atomic mass.

    • The periodic table is arranged by periods and groups, with elements in each period and group having similar characteristics.### Atomic Bonding

    • Atoms bond to form molecules, which are the building blocks of complex matter, including living tissue.

    • A molecule is formed when two or more atoms join together chemically.

    • A compound is a molecule that contains at least two different elements.

    Types of Bonds

    • There are two primary ways atoms bond to form molecules: ionic bonds and covalent bonds.

    Ionic Bonds

    • Ionic bonding is based on the attraction of opposing charges between atoms.
    • When an atom gives up an electron, it becomes positively charged (cation), and when it gains an electron, it becomes negatively charged (anion).
    • In an ionic bond, one atom gives up an electron, and the other takes on an electron, resulting in a net positive and negative charge, which attracts the two atoms together.

    Covalent Bonds

    • Covalent bonding is based on two atoms sharing electrons that orbit both nuclei.
    • In a covalent bond, an outermost electron from one atom orbits the nucleus of another adjacent atom, creating a figure-eight path.
    • This shared electron completes the outermost shell of each atom.

    Atomic Theory

    • The concept of atomism or atomic theory is attributed to Leucippus, and further developed by Democritus of Abdera.
    • John Dalton proposed an atomic theory in the early 1800s, which remains fundamentally sound today.
    • The work of Thomson, Rutherford, and Bohr further developed Dalton's atomic theory.

    Atomic Structure

    • An atom consists of three fundamental particles: protons, neutrons, and electrons.
    • Protons have one unit of positive charge, electrons have one unit of negative charge, and neutrons have no charge.
    • The atom is held together by a strong nuclear force (nuclear binding energy) and electrostatic attraction (electron-binding energy) between the nucleus and orbiting electrons.

    Studying That Suits You

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

    Quiz Team

    Description

    Learn about the early history of atomic theory, its pioneers Leucippus and Democritus, and the etymology of the word 'atom'.

    More Like This

    The Evolution of Atomic Theory Quiz
    5 questions

    The Evolution of Atomic Theory Quiz

    HumaneKhaki avatar
    HumaneKhaki
    Ancient Atomism Quiz
    10 questions

    Ancient Atomism Quiz

    TransparentFreedom avatar
    TransparentFreedom
    Ancient Greeks' Atomism Quiz
    12 questions

    Ancient Greeks' Atomism Quiz

    FantasticForeshadowing avatar
    FantasticForeshadowing
    Epicuro: La fisica degli atomi
    8 questions

    Epicuro: La fisica degli atomi

    SimplifiedFlerovium avatar
    SimplifiedFlerovium
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser