Atoms are the smallest form of elements

 Elements get their names in different ways unique symbol  Each element has its own unique symbol new element  Capital letter indicates a new element

 John Dalton (Atomic Theory)  John Dalton (Atomic Theory) said that each element is made of tiny particles called “atoms” IDENTICAL  All of the atoms of a particular element are IDENTICAL but are different from atoms of other elements

 Subatomic Particles found in the atom NameChargeLocationRelative Mass ProtonpositiveInside nucleus 2000 ElectronnegativeOutside nucleus-orbit the nucleus 1 Way smaller than protons or neutrons NeutronNo chargeInside nucleus 2000

 Positively charged nucleus  Contains neutrons and protons  Neutrons have no charge so overall charge for nucleus is positive

 The IDENTITY of an atoms is determined by the number of protons in the nucleus  Atomic Number-  Atomic Number- the number of protons in the nucleus

 TOTAL number of Protons and Neutrons in the atom’s nucleus

Atomic Number Atomic Mass Atomic number equals the number of protons or electrons Atomic mass equals the number of neutrons + protons.

 Atom correctly modeled  Correct number of subatomic particles  Correct location of subatomic particles  Includes Key  Items used to demonstrate creativity (not just colored on the page)  Atom square includes atomic mass, number and symbol  Correct energy levels and electrons in each

 BoronNeon

 HeliumCarbon

 Finish rest of page 34 and 35  Use your periodic table to find out if the element is a solid, liquid or gas !  We’ll grade and check it tomorrow

 Dmitri Mendeleev  Shows a periodic or repeating pattern of properties of the elements  Gaps- new elements discovered would complete the chart

 Elements arranged by atomic number (number of protons)  Each square gives specific information about the atoms of an element 1. Number at top of the square, # of protons in the nucleus of that atom 2. Chemical Symbol- abbreviation for element’s name; contains one or two letters

 Some elements that have not been named are given a temporary 3 letter symbol  Name of the element is written below the symbol  The number below the symbol tells the average atomic mass of all the elements

symbol  The color of the element’s symbol tells the physical state at room temperature.  White letters like H (hydrogen) indicate a gas  Blue letters indicate a liquid  Black letters indicate a solid

 Background colors of the square indicates whether the element is a metal, non-metal or metalloid.

 Each column (top to bottom) is called a group. similar chemical and physical properties  Elements in a group share similar chemical and physical properties  Groups are read from top to bottom  The groups are labeled at the top of the column  Group are also called “FAMILIES”

row  Each row of the periodic table is called a period left to right  Read from left to right  Horizontal row

 Three main regions  Metals on the left  Nonmetals on the right (except hydrogen)  Metalloid between

element’s location  The element’s location on the table tells us how reactive an element is  Reactive  Reactive - how likely an element is to undergo a chemical change  Atoms in groups 1 and 17 are the most reactive  Elements in group 18 are the least reactive

 Energy Superhighway Can hold 18 electrons Energy Freeway Can hold 8 electrons Energy Street Can hold 2 electrons

 Most elements are metals  Metals conduct electricity and heat well and have a shiny appearance  Can be shaped easily by pounding, bending, or being drawn into a long wire

 Group 1  Alkali metals  Ex: Sodium and Potassium  Group 2  Alkali earth metals  Less reactive

 Atoms of certain elements ALWAYS have the same number of protons, may not always have the same number of NEUTRONS.  Not all atoms of an element have the same MASS NUMBER  Ex: Chlorine- some have 17 protons and 18 neutrons, other chlorine atoms have 20 neutrons

 Sodium – 11 electrons, loses an electron  Chlorine- 17 electrons, gains an electron