Electrical theoryTopic: Structure of the AtomQuestion What is Matter? Matter is any substance that has mass and occupies space. Matter can exist in any of three states: solid, liquid, or gas All matter is made from a combination of atoms. The atom is the basic building block of the universe. To understand electricity, it is necessary to start with the study of atoms. An atom is the smallest part of an elementThe Atoma. The three principal parts of an atom arei. Electronii. Neutroniii. Proton

a. The neutron and proton combine to form the nucleus of the atom. Because the neutron has no charge, the nucleus will have a net positive charge. The number of protons in the nucleus determines the element of an atom. The lines of force produced by the positive charge of the proton extend outward in all directions. The nucleus may or may not contain as many neutrons as protons. The electron orbits around the outside of the nucleus.i. Electron ve chargeii. Proton + ve chargeiii. Neutron no charge

b. The latest scientific measurements suggest protons and neutrons weigh about 1838 times more than the electron, and that the electron is approximately 1/1000 the size of a proton, Many scientists believe that it is almost impossible to accurately measure the size of these particles and the actual size is of no real importance. It is the characteristics of the particles that is of importance

Electron Orbits Atoms have a set number of electrons that can be contained in one orbit, or shell, called an electron orbit, The number of electrons that can be contained in any one shell is found by the formula (2n^2). The letter n represents the number of the orbit, or shell. Use the formula number of electron per shell = 2n^2i. 1st shell = 2*1^2=2 electronsii. 2nd shell = 2*2^2= 8 electronsiii. 3rd shell = 2*3^2 = 18 electronsAn atom can have one or more electrons added to it or taken away. This does not change its elemental classification but it disturbs its electrical balance. If the atom has excess electrons, it is said to be negatively charged. A charged atom is called an ion.

A body containing a number of ionized atoms is also said to be electrically charged. It can be shown that positively and negatively charged bodies are mutually attracted to one another whereas similarly charged bodies repel one another.

Law of electric charge One of the basic laws concerning atoms is the law of charges, which states that opposite charges attract and like charges repel. The negatively charged ELECTRONS are held in their orbits by their attraction to the positively charged PROTONS

The concept of the free electron With some types of materials, such as metals, the outermost electrons in the atoms are so loosely bound that they chaotically move in the space between the atoms of that material by nothing more than the influence of room-temperature heat energy. Because these virtually unbound electrons are free to leave their respective atoms and float around in the space between adjacent atoms, they are often called free electrons. The outer shell of an atom is known as the valence shell. Electrons located in the outer shell of an atom are known as valence electrons. Valence electrons that leave the outermost shell are called free electrons

Summary1. The atom is the smallest part of an element.2. The three basic parts of an atom are the proton, electron, and neutron.3. Protons have a positive charge, electrons have a negative charge, and neutrons have no charge.4. One of the basic laws concerning atoms is the law of charges, which states that opposite charges attract and like charges repel.5. The formula for number of electron per shell = 2n^26. Valence electrons are the electrons located in the outer orbit of an atom.7. These virtually unbound electrons are free to leave their respective atoms and float around in the space between adjacent atoms, they are often called free electrons

Structure of the Atom 1. Matter is any ________________ that has ______________ and ___________ space.2. List the three state of matter ______________________ ______________________ ______________________3. What are the three subatomic parts of an atom? ______________________ ______________________ ______________________4. What charge does each subatomic carry? ______________________ ______________________ ______________________5. Complete 1st shell = 2*1^2=2 electrons 2nd shell = 2*2^2= 8 electrons 3rd shell = 2*3^2 = 18 electrons 4th shell = 6. Valence electron is located in the inner most shell T/F7. Valence electron is located in the _____________ shell.8. Free electron move when ___________ is applied9. List two material that will have free electrons ______________________ ______________________10. Draw an Atom and label same

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