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            <h1>Electromagnetism</h1>
            <span class="subheading">Unit 5</span>
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        <p><b>Electromagnetism</b> is the branch of physics that deals with the electromagnetic force(EMF) that occurs between electrically charged particles. The EMF exhibits electromagnetic fields such as <b>magnetic and electric fields.</b>. <b>Hans Christian Oersted</b> discovered the relation between electricity and magnetism(electromagnetism) of how a electric current creates a magnetic field.</p>
        <img style="margin-left: 200px;" class="img-fluid" src="https://www.aps.org/publications/apsnews/200807/images/Orsted-web.jpg">
        <span class="caption text-muted">Hans Christian Oersted</span>
        <img style="margin-left: 200px"src="https://images.findagrave.com/photos250/photos/2017/267/325_1506338571.jpg" class="img-fluid">
        <span class="caption text-muted">Michael Faraday</span>
        <h1 id="in">Key Terms</h1>
        <p>
          <ul>
            <li>Magnetic Field: the field that revolves around the magnet(from the north pole to the south pole) that shows the area of attraction generated from a magnetic substance(the poles of the magnet being the most attractive).</li>
            <img src="https://www.drpawluk.com/wp-content/uploads/2015/12/magnetic-field-polarity-1024x456.png" class="img-fluid">
            <span class="caption text-muted">Magnetic Field Around a Magnet</span>
            <li>Electric Field: the physical field that originates from electric charge and revolves around each electric charge and exerts a force(attract or repel) on all other charges in the field.</li>
            <img src="https://cdn.kastatic.org/googleusercontent/2-vYxPNTgsokPbHjXKfuKWWx0Adg3HYEROujHHRHLBAh4i2eRbTWEW1Y47AARJopJg803LdLzNzatYAsIdgDvgx4oA" class="img-fluid">
            <span class="caption text-muted">Electric Field Around Two Charges</span>
            <li>(I: A(C/s))Current: measure of the rate of electron flow past a given point in a circuit.</li>
            <li>(V: v(J/C))Potential Difference(Voltage): difference in electric potential energy per unit charge measured at two different points; pressure.</li>
            <li>(R: Ω)Resistance: ability of a material to oppose the flow of an electric current. It does this by converting the electrical energy into other forms of energy.</li>
            <li>(DC)Direct Current: one direction current</li>
            <li>(AC)Alternating Current: a back and forth current.</li>
            <li>Permanent Magnet: magnet made from magnetic material that creates its own magnetic field.</li>
            <li>Electromagnet: magnet created from electron flow.</li>
            <li>Magnetic Flux: measurement of the total magnetic field which passes through a given area. </li>
            <li>Orbital: a mathematically described region around a nucleus in an atom or molecule that may contain zero, one, or two electrons.</li>
          </ul>
        </p>
        <h1>Electron Configuration</h1>
        <p>
          Electron Configuration is the distribution of electrons of an atom or molecule in atomic or molecular orbitals. When configuring a element, the coefficient represents the shell number(starting from the inner shells) and the exponents on the variable represents the number of electrons in that sub-shell. The variables represent their designated section on the periodic table. They are s, p, d, f, they hold 2 electrons(1 Orbital), 6 electrons(3 Orbitals), 10 electrons(5 Orbitals), and 14 electrons(7 Orbitals) respectively. <br>
          To determine the configuration of an atom with multiple electrons, we follow the Aufbau Principle, which is a rule that states that electrons fill atomic orbitals of the lowest available energy levels before occupying the higher levels.
          <img src="https://i.pinimg.com/originals/e9/a4/a2/e9a4a229d6b1e71afd602913d66f258d.jpg" class="img-fluid">
          <span class="caption text-muted">Electron Configuration Table</span>
          <img src="https://useruploads.socratic.org/4H9OMxDSnSeqRjUtjDDy_350px-Electron_configuration_iron.svg.png" class="img-fluid">
          <span class="caption text-muted">Electron Configuration of Iron(Fe)</span>
        If the elctrons are unpaired, then there is magnetism. The arrows represent the direction the electrons spin(up arrows are spinning the same way), and a pair of electrons spin in different directions. According to the Pauli Exclusion Principle, each orbital can only hold a maximum of two electrons with opposite spins. If an orbital has 2 electrons, the electrons start filling in other higher-energy orbitals. Keep in mind if an atom is magnetic, that doesn't mean that the whole element is magnetic.<br>
          <br> According to Hund's Rule, every orbital in a subshell gets one electron before any orbitals get two electrons and those single electrons will have the same spin. <br>
          For instance, Nitrogen will have 3 individual arrows pointing in the same direction rather than have a pair of electrons in the p subshell; this element is paramagnetic(has any unpaired electrons) meaning it is weakly attracted to external applied magnetic fields.
          <img src="img/post-sample-image - 副本 (23).jpg" class="img-fluid">
          <span class="caption text-muted">Nitrogen Electron Configuration</span>
          There is also a shortcut to finding the electron configuration of an element: you group all of the blocks and list the subshells in order and cross a diagonal arrow through them to indicate the order you go in, then count and solve the for the electron configuration. The answer can also be written in a short form where the previous noble gas on the periodic table is in place for some of the subshells and then list the remaining ones:
          <img src="img/post-sample-image - 副本 (24).jpg" class="img-fluid">
          <span class="caption text-muted">Shortcut: Chlorine Electron Configuration</span>
        </p>

        <h1>Electromagnetic Induction</h1>
        <p>
          When electrons move, it creates a magnetic field and becomes a temporary magnet; this is an electromagnet. If the current used to create the electromagnet is DC, then it will have a fixed magnetic flux density and a fixed orientation of poles. Whereas if you use AC, it will have a varying magnetic flux density and alternating poles. The strength of an electromagnet can easily be changed by changing the amount of electric current that flows through it. <br>
          To generate electricity, you have to spin a magnet near a coil to attract/repel the electrons to create a current to then produce electricity. Hydro, Wind, Nuclear, and many more find efficient ways to make a magnet spin to produce energy.<br>
          <img style="margin-left: 250px" src="https://www.e-education.psu.edu/egee401/sites/www.e-education.psu.edu.egee401/files/image/lesson06/Generator.jpg" class="img-fluid">
          <span class="caption text-muted">Magnets inside Generator of a Power Plant</span>
          Electric Currents are produced in wire loops when there is any change in the magnetic flux passing through the wire loop; this current is known as induced current. If either object moves, current is produced. Whereas, if both objects are stationary, there is no current in the wire.
          <br>As magnetic flux increases, the current travels clockwise in the wire. As magnetic flux decreases, current travels counterclockwise in the wire. To describe the electric field induced by a moving magnet, we can use a left-hand rule, where the thumb represents the direction of the magnet's motion and the fingers represent the electric field(forces on the positive charges).
          <h2>Faraday's Law</h2>
          <p>
            Faraday's Law states that the induced voltage is equal to the negative change in magnetic flux over a unit of time. There is a negative sign because the Electromagnetic Force(induced voltage) always opposes any change in the magnetic flux; this is Lenz's Law.
            <img src="img/post-sample-image - 副本 (22).jpg" class="img-fluid">
          <span class="caption text-muted">Faraday's Law Equation(and Lenz's too)</span>
          </p>
        </p>

        <h2>Fun Fact</h2>
        <p>
          When you snap a magnet in half, nothing about the magnetic field really changes. The two halves will attract each other's broken ends and will be able to stick back together again. A big magnet is made of many tiny magnets(with north and south poles) called magnetic domains. So if you cut a magnet in half, the newly cut faces will become the new north or south poles of the smaller pieces.
          <img class="img-fluid" src="img/post-sample-image - 副本 (21).jpg"></img>
          <span class="caption text-muted">Snapping Magnets</span>
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