Chapter 5 The Periodic Table

5-1 Organizing the Elements What does the word “periodic” mean? Periodic: recurring at _______ intervals Periodic table – is an ___________ of elements in__________ based on a set of properties that repeat from _________ to row

Mendeleev 1869 See Figure 3 on page 127 Arranged elements according to increasing _____________ in rows Put elements of similar properties in the same __________ Left blank spots in table which predicted _________ of elements not yet discovered

Evidence Supporting Mendeleev’s Table Named eka-aluminum to the element that belonged one space ________ aluminum on the table French chemist discovered a new element and named it ________ (Ga) Gallium is a soft metal used in ________ signals

Similarity of the two Eka-aluminum and Gallium were similar in properties, so they were determined to be the ________ The close match between Mendeleev’s _________ and the actual properties of new elements showed how ________ his periodic table could be

Questions 1.Which of the following is a symbol for an element? a.Aluminum b.Al c.al d.AL

Questions 2. Is flammability a physical property or a chemical property?

Questions 3. What happens to the composition of matter during a physical change? Does it change or remain the same?

Questions 4. What does the atomic number of an element represent?

Question 5. Isotopes of element have different numbers of a.Neutrons b.Electrons c.Protons d.nuclei

Question 6. True or False : Electrons in atoms occupy orbitals in energy levels

5-2 The Modern Periodic Table _____________ developed the periodic table before the discovery of___________. In the modern periodic table, elements are arranged by increasing _____________

Periods Each_______ in the table of elements is called a __________ Period 1 has ________ elements Periods 2 and 3 have ________ elements Periods 4 and 5 have ___________elements Period 6 has ________elements There are ________ periods total on the periodic table The number of _____________ per period varies because of the number of available orbitals increases from energy level to energy level

Groups Each _________ on the periodic table is called a __________ The elements within a group have similar _________ Properties of elements__________ in a predicable way when atomic number are used to arrange elements into groups The pattern of repeating properties is the _________ There are ________ groups on the periodic table

Atomic Mass _____________ is a value that depends on the distribution of an element’s isotopes in nature and the masses of those isotopes An atomic mass unit________ is defined as one twelfth the mass of carbon-12 atom

Average Atomic Mass Weighted __________ of the atomic masses of the naturally occurring isotopes of an element

What is the aver. atomic mass of the chlorine? IsotopeIsotope Mass (amu) % Abundance Chlorine Chlorine

Weighted Averages Average Atomic Mass = (isotope mass)(relative abundance[dec]) + (isotope mass)(relative abundance[dec]) ( )( amu) + ( )( amu) = ___________

ISOTOPES Atoms of the _____________ that differ in __________ Have the same # protons but different # neutrons

Classes of Elements Elements are classified as_______, ___________, and __________ Metal: –Good conductor of heat & electricity –____________ –able to be drawn into a fine wire –Malleability – can be hammered or rolled into thin____________ Nonmetal –Poor conductor of heat & electricity –_____________ Metalloids –Some characteristics of ____________ & _______________

Transition Metals ________________ are elements that form a bridge between the elements on the left and right sides of the table

The Lanthanides The ___________ elements with atomic numbers from 58(cerium, Ce) to 71(lutetium, Lr) Similar in chemical and physical properties

The Actinides The ________________ elements with atomic number from 90(thorium, Th) to 103(lawrencium, Lr)

Variation across a period Across a period from left to right, the elements become ________ metallic and more nonmetallic in their properties Most __________ metals are on the left side of the table Most reactive________ are on the right in Group 17

5-3 Representative Groups __________ electron – is an electron that is in the ________ occupied energy level of an atom Elements in a _______ have similar properties because they have the _______ number of valence electrons Valence electrons explain the location of _______, hydrogen has a ______ electron

Alkali Metals Elements in Group ______ are called ______ metals. ________ valence electron and are extremely _________ The reactivity of alkali metals ___________ from the top of Group 1A to the bottom

The Alkaline Earth Metals The elements in Group _______ are called _____________metals All alkaline earth metals have ___________ valence electrons They are ________ than group 1A Differences in reactivity among the alkaline earth metals are shown by the ways they react with _________ Calcium, strontium and barium react easily with _______ water Magnesium will react with________water. No change appears to occur when beryllium is added to water

The Boron Family Group ________ contains the metalloid ________. ___________ is the most abundant metal in the Earth’s crust ________that contains boron is used to make laboratory glassware such as flasks

The Carbon Family Group _______ contains nonmetal carbon Two ________ – silicon and germanium Two metals – lead and ________ Except for _______, most of the compounds in your body contains carbon __________ is the second most abundant element in the Earth’s crust

The Nitrogen Family Group ______ contains two nonmetals – nitrogen and phosphorus _____ metalloids – arsenic and antimony One metal –bismuth Besides nitrogen, ___________ often contain phosphorus

The Oxygen Family Group _______ has three nonmetals – oxygen, sulfur, and selenium Two metalloids – tellurium and polonium All have_______valence electrons ___________ is the most abundant element in the Earth’s crust

The Halogens The elements in Group _______ are called halogens They have ________ valence electrons Despite their physical differences, the halogens have ________ chemical properties They are highly reactive ___________ _________ is the most reactive

The Noble Gases The elements in Group_______ are called the noble gases Helium has _______ valence electrons All other noble gases have ______ valence electrons The noble gases are________ and________ and extremely_________ All the noble gases except ______ are used in “neon” lights