Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
+ Atomic Structure Ms. Nail: 7th and 8th Grade Science WHAT is an Matter? MATTER is: Anything that has mass and takes up space. Matter is every thing around you. What are the 3 States of Matter? 1. SOLID: Matter with a definite shape and volume. The particles are close together and vibrate. 2. LIQUID: Matter that has definite volume but no definite shape. The particles are further apart , and can move freely. 3. Gas: Matter that does not have a definite shape or volume. The particles are spread apart and move at high speeds in all directions. So….What is an ATOM anyway? An ATOM is a small particle that is a building block of all matter. What are the 3 particles that an atom is made of? 1. PROTONS 2. NEUTRONS 3. ELECTRONS 1. Protons (+) Positively particles charged Heavy particles, makes up half the mass in an atom. Found in the nucleus of the atom to the atomic number of the atom ++ + +++ + + - - Equal Equal to the number of electrons - + - 2. Neutrons (-) - - Neutral ++ + +++ + + - - - particles; have no electric charge Heavy particle, makes up half the mass in an atom. Found in the nucleus of the atom A NEUTRON WALKS INTO A RESTAURANT AND ASKS, HOW MUCH FOR A COKE? THE WAITRESS REPLIES, FOR YOU, NO CHARGE!! GET IT? NO CHARGE? The POSITIVE charge on PROTONS (+) and NEGATIVE charge on ELECTRONS (-) cause the two to be ATTRACTED to each other and CANCEL each other out. This attraction is what holds an atom TOGETHER (similar to a magnet). 3. Electrons (-) - Negatively charged particles Found outside the nucleus of the atom, in the electron orbits/energy levels Move so rapidly around the nucleus that they create an electron cloud Very light and adds almost no mass to the atom but is responsible for the volume in an atom. Equal to the number of protons ++ + ++ + + + - - - - - - Valence Electrons What is a VALENCE ELECTRON? An electron that is found on the OUTERMOST energy level/shell. Valence electrons are responsible for BONDING. The number of valence electrons can range anywhere from 1 to 8 on the OUTERMOST energy level, depending on what PERIOD they are found on, on the PTE. Valence electrons can be SHARED or GIVEN AWAY. Orbitals/Energy Levels/Shells ELECTRONS are found in areas called SHELLS. A shell is sometimes called an ENERGY LEVEL OR ORBITAL. Shells are RINGS that surround the CENTER of an atom. ENERGY LEVELS + Atomic Number The number of protons in the nucleus of an atom - - + ++ What would be the atomic number of this atom? - + ATOMIC MASS The total number of protons and neutrons in an atom’s nucleus Expressed in Atomic Mass Units (amu) Each proton or neutron has a mass of 1 amu What would be the mass number of this atom? + - 3 + ++ 4 3 protons + 4 neutrons = a mass number of 7 amu Why did we not account for the electrons when calculating the mass number? - - + When trying to remember all of those rules when calculating the Atomic Structure of an Atom, just remember THIS: Atomic Number is the same # of Protons is the same # of Electrons Mass Number minus - Atomic Number =‘s # of Neutrons