Do First Actions: In 5 minutes, I will collect your cell phones and you need place your bags and all your papers in the front. Do First: Write quiz today.

Agenda Quiz Interactive Simulation Notes

Quiz YOU MAY WRITE ON THE QUIZ Write the rich raider pledge at the top of your quiz: I ________ pledge that I have neither given nor received any assistance on this assignment. When you are done with the quiz: 1. Turn in your quiz to the Mrs. Jain 2. Get your cell phone and backpack 3. Start the interactive simulation activity on your phone

ATOMIC STRUCTURE http://learn.genetics.utah.edu/content/cells/scale/

Atomic Structure An atom is the smallest particle of matter that retains the properties of the element Realizing its size… Atoms are composed of three subatomic particles

1 AMU (slightly more massive than proton) Atomic Structure PARTICLE MASS CHARGE ELECTRON Virtually none Negative PROTON 1 AMU Positive NEUTRON 1 AMU (slightly more massive than proton) neutral In a neutral atom, the # of electrons must equal the # of protons The identity of the atom is based on the # of protons

Atomic Structure When atoms of the same element contain different #s of neutrons they are called isotopes A neutral atom has an overall charge of zero When an atom loses or gains electrons, an ion forms. A cation forms when an atom loses electrons (+ve charge) An anion forms when an atom gains electrons (-ve charge)

Valence electrons are the electrons in the outer most energy level.

Atomic Structure NUCLEUS Contains Protons (p+) and Neutrons (n) Characterizes the mass of an atom 4th energy level (32 e-) 3rd energy level (18 e-) 2nd energy level (8 e-) 1st energy level (2 e-) ELECTRON CLOUD Region around nucleus where electrons (e-) move Characterizes the volume of an atom

Atomic Number: # of protons in nucleus (also the # of electrons if neutral) 6 C Chemical Symbol: abbreviation for the name of an element (1st letter caps, 2nd letter lower case) Average Atomic Mass: average mass of the mixture of isotopes 12.001

DYL What is the atomic number for Lead? How many electrons does a neutral Lithium have?