2 Chemical vs physical properties Chemical propertyA property that describes an ability to change into a different substanceCan only be observed by changing the matterPhysical propertyA property that can be observed without changing the composition of the matterA property that can usually be observed using senses
3 MetalsMetals – are elements that are good conductors of electric current and heatThey are shiny and bendableWhere in the periodic table are metals found?At the left side and extending more than halfway across the tableWhat in the classroom contains metal? (raise your hand)
4 Physical properties of Metals The physical properties of metals includeLuster – shiny and reflectiveMalleability – material that can be hammered or rolled into flat sheets or other shapes. ex: copperDuctility – material that can be pulled out or drawn into long wire. Ex: copperConductivity – 2 typesThermal conductivity -ability of an object to transfer heatElectrical conductivity -The ability of an object to carry electric current
5 Metals Have low specific heats Specific heat - is the amount of energy required to raise the temperature of 1 gram of a material by 1 kelvinWhat does this mean?Only a small amount of energy is required to raise the temperature of a metal
6 Metals Some metals are magnetic Iron, cobalt, and nickel Most metals are solids at room temperatureMercury – only metal that is a liquid at room temperatureUsually do NOT combine with each otherReadily combine with nonmetals
7 Activity page 80Identify the properties of metals exhibited by each of the objects located at the top of the page.
8 Chemical Properties of metal Reactivity – speed with which an element combines or reacts with other substancesWhy do metals react?Metals usually react by losing electrons to other atomsEx: sodium (Na) reacts strongly with waterCorrosion – deterioration of a metal due to a chemical reaction in the environment
9 Apply it page 811. some of the silver forks shown have lost their luster, they have become more tarnished.This is an example of _______________________2. what properties of gold and platinum make these metals desirable for jewelry?
10 How are metals classified In the periodic table, metals are classifies asAlkali metalsAlkaline earth metalsTransition metalsMetals in mixed groupsLanthanidesActinides
11 Types of metals Alkali metals – an element in Group 1 Most reactive Mostly found in compoundsPure alkali metals are shiny and softLow density and melting pointsAlkaline earth metal – an element is Group 2Harder and denserMelt at higher temperaturesReactive, but not with alkali metalsMostly compounds
12 Types of Metals Transition metals – elements in Groups 3 – 12 Ex: iron, copper, nickel, gold, and silverHard and shiny solidsHigh melting points and high densitiesGood conductors of heat and electric currentVery malleableLess reactive
13 Types of metals Mixed groups – only some elements in Group 13-16 Ex: tin (Sn) and Lead (Pb)LanthanidesTop row are lanthanidesLanthanides are used to make laser lightEx: used for surgery and cutting metalsActinidesSecond row, below lanthanidesMost artificially made in laboratories
14 lets review what we learned What does it mean to be poor conductors of heat or electricity?Heat or electricity is not easily transferred through materialsWhat types of metals do we have?Alkali metals, alkali earth metals, transition metals, mixed groups, lanthanides, and actinidesWhat does malleable mean?Material that can be hammered or rolled into flat sheets
15 Let review what we learned What does ductile mean?Material that can be pulled out into long wiresWhat are they 2 types of conductivityThermal conductivity and electrical conductivityWhat does reactivity mean?Speed at which an elements combines or reacts with other substance.
16 NonmetalsNonmetals – is an element that lacks most of the properties of a metalCarbon (C), Nitrogen (N), Phosphorus (P), Hydrogen (H), and oxygen (O) are nonmetals found in your DNA
17 Physical properties: Nonmetals Nonmetals are poor conductors of electric current and heatSolid non metals tend to be dull and brittleLow densityAre gases at room temperatureEx: air you breath is mostly nitrogen and oxygenCarbon, sulfur (S), and iodine (I) are solids at room temperatureOnly Bromine is liquid at room temperature
18 Chemical Properties: Nonmetals Usually gain or share electron when they react with other atomsNonmetals react with metalsWhat happens?Electrons move from the metal atom to the nonmetal atomEx: sodium and chlorine react to form table salt (NaCl)- an electron moves from the sodium atom to the chlorine atom
19 Chemical Properties: Nonmetals Able to form compound with other nonmetalsIn these compounds, the atom share their electron to form bondsWhen 2 or more atoms bond this way, they form a moleculeWater molecule (H20)Apply it page. 88