Atomic Structure Notes 2014

2 Atomic Structure Subatomic particles include ________, _________ and _________. protons neutrons electrons ________ and _________ are inside the ________ Protonsneutrons nucleus __________ are found __________ the nucleus Electrons orbiting Atoms are made up of ________ _________ smaller particles

3 Atomic Pieces Protons have a _________ charge and a mass of ________. Neutrons have a _________ charge and a mass of _________. Electrons have a __________ charge and a mass that is so ______ that we consider electrons to have ____ mass! positive 1 AMU (Atomic Mass Unit) neutral 1 AMU negative small “NO”

4 Element Symbols Every element has a _______ on the Periodic Table. symbol The symbol is either 1 or 2 letters, where the first is always a ________ letter, and the second is always a _____ letter… capital small HHeCCa

5 Atomic Number Elements in the Periodic Table are organized by _______ _______. Atomic number The atomic number is the same as the number of ________. protons Every element has a _________ number of protons, and therefore a ________ atomic number. different

6 Number of Pieces In a ________ atom, the number of _______ always equals the number of __________. neutral protons electrons #P = #E

Electron Practice 7 SymbolAtomic #ProtonsElectrons Mg O Au Ti

8 Atomic Mass How do you find the _____ of an atom? mass (________ have mass, _________ have mass, _________ have ____ mass.) Protonsneutrons electrons“NO” Since protons and neutrons are the only particles that have mass, ____ them together to find the atom’s mass. add

9 Element Symbols Element symbols contain the atomic number, mass number and element symbol. X Mass number Atomic number Element symbol

10 Number of Neutrons If you know the atomic number and the atomic mass of an element, you can find the number of _________. neutrons Mass - #P = #N

11 Examples: Find theFind the –number of protons –number of neutrons –number of electrons –Atomic number –Mass Number –Name Na 23 11

12 Examples: n Find the –number of protons –number of neutrons –number of electrons –Atomic number –Mass Number –Name Br 80 35

13 Examples: n If an element has an atomic number of 34 and a mass number of 78 what is the –number of protons –number of neutrons –number of electrons –Complete symbol –Name