Atomic Structure

What is an atom? Atom: the smallest unit of matter that retains the identity of the substance

Atomic Structure Atoms are composed of 2 regions: Nucleus Electron Cloud

The Nucleus Nucleus: the center of the atom that contains the mass of the atom The Nucleus contains Protons and Neutrons. Protons: positive charge Neutrons: neutral charge

The Electron Cloud Electron cloud: region that surrounds the nucleus that contains the space/volume in the atom Contains the Electrons Electron: negative charge Has relatively no mass

An atom must be balanced! In an atom: The # of protons = the # of electrons The neutrons have no charge; therefore they do not have to equal the number of protons or electrons

How can we find the number of protons, neutrons, and electrons? Atomic number: this number indicates the number of protons in an atom Atomic Mass: the number of protons and neutrons in the atom.

This information is found on the Periodic Table 1 H 1.008 Atomic Number Symbol Atomic Mass Hydrogen Element’s Name

Calculating the neutrons How can we find the Neutrons? # of neutrons = mass # - atomic #

What about the electrons? The electrons are equal to the number of protons Atomic # = protons = electrons

Determining the number of protons, neutrons and electrons Li has an atomic number of 3 and a mass number of 7 Protons = ____ (atomic #) Neutrons= ____ (mass # - atomic #) Electrons = ____ (electrons = protons) Ne has an atomic number of 10 and a mass number of 20 P = ____ N = ____ E = ____

How are the particles arranged in an atom? The Bohr Model of the atom: Nucleus - protons and neutrons 3rd ring holds up to 18 e- 1st ring holds up to 2 e- 4th ring holds up to 32 e- 2nd ring holds up to 8 e-

What does Carbon (C) look like? Atomic # = 6 Mass # = 12 p+ = 6 no = 6 e- = 6 6 p and 6 n live in the nucleus

What does Fluorine (F) look like? Atomic # = 9 Mass # = 19 p+ = 9 no = 10 e- = 9 9 p and 10 n live in the nucleus

Atomic Structure and Bohr Model Practice On the front… Boron (B) Nitrogen (N) Calcium (Ca) Nickel (Ni) On the back… Sodium (Na) Beryllium (Be) Neon (Ne) Sulfur (S)

Bohr Model Trading Cards Write your name on the bottom right corner of paper. Choose 2 elements (with an atomic # less than 92) from the Periodic Table. Write the info (atomic #, symbol, name and atomic mass) for those elements on the 2 papers provided.

Bohr Model Trading Cards Trade with 2 different people. Write your name in the bottom right corner and then draw the Bohr Model for that element on the back. Use a marker and trace over your Bohr Model. Make it look pretty  Tape it up anywhere on the wall when you are finished.