Presentation on theme: "Elements and the Periodic Table Chapter 4. The Atom Chapter 4.1 pg 124-130 Cornell Notes."— Presentation transcript:
Elements and the Periodic Table Chapter 4
The Atom Chapter 4.1 pg Cornell Notes
Essential Questions What is the structure of the atom? What are the 3 subatomic particles? What particles make up the nucleus?
1. The Atom Atom: the smallest particle of an element (pg: ) Nucleus: the center of an atom; also where the protons and neutrons can be found (pg:128)
electron clouds nucleus At the center of the atom is a tiny nucleus containing protons and neutrons. Surrounding the nucleus is a cloud-like region of moving electrons.
A. Proton Proton: positively charged particles in an atom’s nucleus; mass = 1 amu (atomic mass unit) Number of protons identifies the element Number of protons and identifies the element = atomic number
B. Neutron Neutron: Particles with no charge in the nucleus; mass = 1 amu # of protons + the # of neutrons = mass number/atomic mass Adding or taking away neutrons DOES NOT change the atom, it makes different isotopes
Isotopes- atoms of the same element that have different numbers of neutrons. Example: Carbon-12 = 6 neutrons, Carbon-13 = 7 neutrons, and Carbon-14 = 8 neutrons (pg: 130)
Isotopes or different elements? T has 20 protons and 20 neutrons Z has 20 protons and 21 neutrons T and Z are isotopes – same # of protons, different # of neutrons A has 31 protons and 39 neutrons E has 32 protons and 38 neutrons A and E are different elements – different # of protons
C. Electron Electron: negatively charged particles in the electron cloud; mass = 0 amu (very small It takes 1800 electrons to equal the mass of 1 proton) # of electrons = # of protons in a neutral atom Valence Electron- The electron(s) in the shell farthest from the nucleus
electron clouds nucleus P+ N Protons (+) Neutron (0) Electrons (-) Valence electron
P+ N Protons (+) Neutron (0) Electron (- ) Valence electrons
With your partner: Protons –Can you name the charge, location and mass Neutrons –Can you name the charge, location and mass Electrons –Can you name the charge, location and mass
The electrons are arranged in a particular order. The electrons fill the energy shells closest to the nucleus first and then fill outward: The first energy shell can hold up to 2 electrons The second energy shell can hold up to 8 electrons The third energy shell can hold up to 18 electrons The fourth energy shell can hold up to 32 electrons
Electron Shell Diagram – * First Energy Level 2 electrons Second Energy Level 8 electrons Third Energy Level 18 electrons Fourth Energy Level 32 electrons
Sub-Atomic Particle Review Subatomic particleAtomic mass in atomic mass units chargelocation Proton1 amu+ positive nucleus Neutron1 amu0 neutral nucleus Electron0 amu_ negative Orbits around nucleus in electron cloud
Review ElementAtomic numberProton numberAtomic mass (rounded) NeutronsElectrons C Carbon Na Sodium Si Silicon O Oxygen
Organizing the elements Chapter 4.2 Cornell Notes
4.2 Essential Questions How is the Periodic Table of the Elements (PTE) arranged?
1. Mendeleev -Russian Chemist who looked for patterns of properties of the elements. -He grouped the elements according to the patterns and by increasing atomic mass. -This allows us to predict the properties of missing elements.
2. Atomic Weight The average of all the masses of all the isotopes of an element
3. Using the periodic table The properties of an element can be predicted from its location on the periodic table Elements are arranged in order of increasing atomic weight
4. How to read the Periodic Table C Atomic Number- number of protons Atomic Symbol First letter always capitalized, second never Atomic Mass- protons +neutrons
4. How to read the Periodic Table (partner review) Li
5. Periods Horizontal rows (pg ) The properties gradually change as you move left to right across the Periodic Table. Indicates the number of electron shells
6. families or Groups Vertical Columns (pg ) Similar Physical and Chemical properties Indicates the number of Valence Electrons
6. Families or Groups
Review: With your partner How is the PTE organized? Vertical columns? Horizontal rows? What order are the elements in?
Essential Questions Where are metals, nonmetals and semi metals on the PTE? What are the properties of metals, nonmetals and semimetals? What are the properties of elements in each family?
Metals, Nonmetals, and Semimetals Metals and nonmetals are separated by a stair-step line on the right side of the table. Metals are found to the left of the line and nonmetals are found to the right of the line. Elements that border the line on both sides are called semi-metals.
The Periodic Table Metals NonmetalsSemimetals
A. Metals 1. Found on the left of the periodic table. 2. Have only a few electrons in outer shell. 3.Most are solid, shiny, good conductors of heat and electricity, malleable, are ductile. 4. Alkali metals – Family/Group 1 5. Alkaline earth metals – Family/Group 2 6. Transition metals – Families/Groups 3- 12
1.Found on the right side of periodic table B. Nonmetals 2. Most are dull, not malleable or ductile, not good conductors of heat or electricity. 3.Valence electron shell is mostly or completely full
C. Semi-Metals (metalloids) 1.Found along the zig-zag (stair step) line on the periodic table; also called metalloids 2. They are semi-conductors that have properties of both metals and non-metals. 3.The outer electron shell is about half full.
With your partner Can you identify where the metals, non metals and semimetals are on the PTE What are the properties of metal? What are the properties of a nonmetal? What are the properties of a semimetal?
Valence Electrons Electrons that are in the outer shell Valence Electrons determine reactivity A full shell is stable The valence shell is complete with 8 electrons
reactivity Empty or Full non reactive (inert) Close to full or close to empty very reactive Half full or half empty not as reactive
Alkali Metals Alkaline Earth Metals Transition Metals Boron Family Carbon Family Nitrogen FamilyOxygen FamilyHalogen FamilyInert / Nobel Gases LanthanidesActinides
A. Alkali Family (1 Valence Electron) The most reactive metals Shiny and soft Can be cut with a knife
B. Alkaline Earth Metals (2 Valence Electrons) Very Reactive Silver colored metals, more dense than family #1
C. Transition Metals Have 1-2 Valence electrons Includes many common metals such as copper, iron, gold, and silver
D. Boron Family (3 valence electrons) Reactive Solids
E.Carbon Family (4 Valence electrons) Reactivity varies All are solids Carbon based molecules make up all living things
F.Nitrogen Family (5 valence electrons) Reactivity varies Nitrogen is the most common element in the atmosphere
G. Oxygen Family (6 valence electrons) Reactive
H. Halogen Family (7 valence electrons) -These are the MOST REACTIVE NONMETALS -Some are used as cleaners
I.Inert Gases (Noble Gases) (8 valence electrons) Stable – Not reactive!! All are nonmetals, and all are gases Helium only has 2 valence electrons because it only HAS 2 electrons total
Lanthanide and Actinide Families (2 valence electrons) These are a part of the transition element family
Liquids, gases and semi metals The majority of elements are solids (so we are not labeling those) Find and mark (be creative) the liquids Find and mark (be creative) the gases Darken the stair step line for metalloids and outline the boxes of elements that are semi- metals