I. Atomic Structure II. Masses of Atoms Mass Number Ion Isotopes

Elements and atoms Elements on the periodic table are made of atoms. Atoms are the smallest form of matter. All atoms in an element look the same. The structure of an atom determines how that atom will react with other atoms of a different element Atom: Element: 8 O 15.99999

Atomic Structure & Atomic Number Proton = p+ Electron = e- Neutron = n0 Atomic # is the number at the top of each block on the periodic table Atomic # = #p Neutral Atom #p = #e- 1 H 1.00784

Atomic Mass (Mass Number) – the number of particles in the nucleus of a single atom Atomic Mass= protons + neutrons always a whole number NOT on the Periodic Table! © Addison-Wesley Publishing Company, Inc.

Naming a single atom is called atom notation Each element has billions of atoms so it is important to name each one correctly. Naming a single atom is called atom notation

Mass # Atomic # Atom Notation Hyphen notation: carbon-12 1. Nuclear Symbol: Mass #atomic #symbol 2. Hyphen Notation: element name – mass # Hyphen notation: carbon-12 Nuclear symbol: Mass # Atomic #

Atom Notation - Name this atom using both forms of notation REMEMEBER!!! # p = atomic # Mass # = #p + #n Hyphen Notation: Oxygen – 16 Nuclear Symbol: O 16 8

Identifying parts of an atom from the atom notation 17 37 20 Chlorine-37 atomic #: mass #: # of protons: # of electrons: # of neutrons:

Neutral Atom Remember: Neutral = same number of (+) and (-) Neutral Atom = same number of p+ and e- Atoms are not always neutral. Sometimes e-move around – this causes and atom to become an ion.

Ion – an atom that gains or loses e-, causing the atom to be charged An atom with an unequal amount of p+ and e- causes a charge to form Loses e- (More protons) = (+) charge Gains e- (More electrons) = (-) charge The quantity of the electrons lost or gained determines the charge quantity

Identify as a neutral atom or an ion

Name the ion An ion can only be named using the nuclear symbol or if the picture is given. Nuclear Symbol: You cannot identify an ion or name an ion by hyphen notation. 19 F -1 9

Ion notation – is only identified in nuclear symbol or picture 8 16 10 Oxygen - 16 atomic #: mass #: # of protons: # of electrons: # of neutrons: -2

Journey into an Atom Read the introduction – pay attention to the Bean Key on the front page. Collect the data from each atom (bag of beans) on the lab table. Use this data to determine both types of atom notation. Do not worry about electrical charge at the moment.

PEN Table – with ions Collect a periodic table from the front table in the pink folder. Use the periodic table to help you fill in the PEN table. Remember to pay attention: Is it a neutral atoms or ion

Isotopes - Atoms of the same element with different mass numbers. Carbon – 12 Carbon – 14 © Addison-Wesley Publishing Company, Inc.

Isotopes © Addison-Wesley Publishing Company, Inc.