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A Little Periodic Table History…. History of the Periodic Table. Dmitri Mendeleev , a Russian scientist born in Siberia in 1834, is known as the father of the periodic table of the elements
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History of the Periodic Table • Dmitri Mendeleev, a Russian scientist born in Siberia in 1834, is known as the father of the periodic table of the elements • The periodic table is designed to help you predict chemical and physical properties of elements
Method Behind the Madness • Mendeleev set out to find a pattern in the elements • He wrote facts on paper cards for each element • Melting Point • Density • Colors • Atomic Masses
Method Behind the Madness (cont) • After laying all of his cards out he noticed that by arranging them according to their properties they were arranged in order of increasing atomic mass • Mendeleev was even able to use the patterns in his table to predict the properties of undiscovered elements • The first periodic table was published in 1869 The Genious of Mendeleev's Periodic Table - TedEd Mendeleev Song
Big Science Idea Today, elements are arranged in order of increasing atomic number on the periodic table
Element Location Elements are located in three main categories on the periodic table based on their physical properties • Metals • Nonmetals • Metalloids
Physical Properties Physical Property - a property of matter that can be observed or measured WITHOUT CHANGING the substance
Examples of Physical Properties • Color/Texture • Mass – How much matter is in an object • Malleable – Can be pounded/rolled into a shape • Ductile – Can be stretched into a long wire • Density – How tightly mass is packed into an object
Metals Most elements are metals. The 88 elements to the left of the stair-step line are metals or metal-like elements. • Physical Properties of Metals: • high luster (shininess) • good conductors of heat and electricity • high density (heavy for their size) • high melting point • ductile • malleable
Non-Metals Non-metals are found to the right of the stair-step line. Their characteristics are opposite those of metals. Physical Properties of Nonmetals: • no luster (dull appearance) • poor conductor of heat and electricity • brittle (breaks easily) • not ductile • not malleable • low density • low melting point
Metalloids Elements on both sides of the zigzag line have properties of both metals and nonmetals. These elements are called metalloids. Physical Properties of Metalloids: • solids • can be shiny or dull • ductile • malleable • conduct heat and electricity, but not as well as metals Antimony (Sb)
Scientists organize elements according to their physical and chemical properties Big Science Idea
How to Read the Periodic Table • The Periodic table is designed to help you predict what an element's physical and chemical properties are • You can also predict what elements will bond with each other
Vertically into Groups (also called Families) Horizontally Into Periods Elements are arranged: Periodic Table Bitesize (only show part 1)
Periodic Table Arrangement Groups or Families • Vertical columns on the periodic table Periods • Horizontal rows of the periodic table
If you looked at one atom of every element in a group you would see…
Each atom has the same number of valence electrons (the electrons in its outermost shell).Think back to the Bohr Model An example…
The group 2 atoms all have 2 electrons in their outer shells Be (Beryllium) Atom Mg (Magnesium) Atom
Valence Electrons • Effect the way an atom bonds, which determines many of the chemical properties of the element • Atoms can have anywhere between 1 and 8 valence electrons • This is why elements within a group usually have similar chemical properties
Chemical Properties A chemical property is a characteristic that is observed when a substance changes into a different substance
Examples of Chemical Properties • Combustible – capable of igniting at higher temps • Corrosion Reactivity • Flammable – capable of igniting • Oxidation – rusting or tarnishing
Metals – Reactivity Reactivity decreases from left to right Metal Reactivity
Nonmetals – Reactivity Reactivity increases from left to right Not Reactive X
If you looked at an atom from each element in a period you would see…
Each atom has the same number of electron holding shells. An example…
The period 4 atoms each have 4 electroncontaining shells 4th Shell K (Potassium) Atom Kr (Krypton) Atom Fe (Iron) Atom
Each group has distinct properties The periodic Table is divided into several groups based on the properties of different atoms For example…
Periodic Table • Information on the periodic table: • Atomic number • Atomic symbol • Mass number (Atomic Mass) • Element name • Group and period numbers
Think Inside the Box Atomic Number: Number of protons (also the number of electrons) in an atom of an element. 8 O Element’s Symbol:An abbreviation for the element. Oxygen Element’s Name 16 Atomic Mass: Number of protons + neutrons.
Chemical Symbols • Shorthand way of representing the elements • Usually one or two letters • Usually taken from the name of the element • Carbon-C, Calcium-Ca, Hydrogen-H, Iodine-I, Oxygen-O, Chlorine-Cl
Chemical Symbols • Some symbols come from their Latin name: • Gold-Au--aurum • Silver-Ag--argentum • Iron-Fe--Ferrum • Mercury-Hg--hydrogyrum
How do we know the number of subatomic particles in an atom? • Atomic number: this number indicates the number of protons in an atom of a particular element • Ex: Hydrogen’s atomic number is 1 • So hydrogen has 1 proton • Ex: Carbon’s atomic number is 6 • So carbon has 6 protons **The number of protons is a unique property that identifies an element. Ex. 2 protons = He, 29 protons = Cu
Atomic Mass • Atomic Mass Unit (amu) is used to measure the particles in atoms • Protons & Neutrons are about 1 amu • Electrons are MUCH smaller • It takes about 2,000 electrons to equal 1 amu • Atomic Mass = Protons + Neutrons
3 Atomic # Li Symbol 6.941 Mass # Pick an element off the Periodic Table and draw and label it just like this one!
Group and Period Numbers Period Numbers Group Numbers
How Can I Find Out the Number of Protons and Electrons? Atomic No. = # of protons Since protons & electrons are EQUAL...the atomic no. also tells you the # of electrons *Atomic # = # of Protons = # of electrons*
APE Let’s take a look: A = Atomic number P = Number of protons E = Number of electrons These are all the same number!! So Atomic # = # of Protons = # of electrons
Then How Can I Find Out the Number of Neutrons? Mass Number = number of protons + number of neutrons So Neutrons = Mass Number – Atomic Number
MAN • Now let’s look at MAN: • M= Atomic Mass • - A= Atomic Number • N= # of Neutrons Simple math! Mass minus atomic number gives you the number of neutrons!!!
APEMAN Let’s work a couple together Let’s try Nitrogen!
Nitrogen Boron 5 7 A= P= E= M= -A= N= A= P= E= M= -A= N= 5 7 5 7 11 14 5 7 6 7