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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.
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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 • 1875- 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 • Which of the following is a symbol for an element? • Aluminum • Al • al • 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 • Neutrons • Electrons • Protons • 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
Weighted Averages • Average Atomic Mass = • (isotope mass)(relative abundance[dec]) + (isotope mass)(relative abundance[dec]) • (0.75771)(34.96885amu) + (0.24229)(36.96590amu) • = ___________
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