UNIT 5 Patterns and Compounds Chemistry in Action UNIT 5 Patterns and Compounds

Think About It Name some of the elements you have seen today. Common Objects made of minerals How are the symbols of the elements related to their names? What are some elements that are part of your vitamins? On a dry day, you walk across a carpet and touch a doorknob. You feel a spark. What happened?

Atoms and Elements Everything that has mass and occupies space is call matter The primary substances of all matter are elements 114 different kinds 88 occur in nature 26 are synthesized Element Song

Naming Chemical Elements Give the names of the element that corresponds to each of the following chemical symbols: a) Zn b) K c) H d) Fe zinc b) potassium c) hydrogen d) iron funtrivia.com/trivia- quiz/Common Names For Everyday Chemicals

Elements and Symbols Elements are the primary substances of matter Origin of Elements Chemical symbols are one- or two- letter abbreviations for the names of the elements. The physical properties of an element are those characteristics such as colour, density, melting and boiling point that we can observe or measure without changing the identity of the element

The Periodic Table By the late 1800’s, scientists began to notice that certain elements looked alike and behaved much the same way in reactions Dmitri Mendeleev proposed arranging elements in groups according to their similar properties = PERIODIC TABLE Elemental Funkiness Check out the link to the TED Talk videos in the title.

Groups and Periods GROUPS (vertical columns) Numbering systems: Values 1 – 18 Representative elements use letter “A’ with the numbers 1A – 8A; transition elements use “B” Roman numerals may be used IA to VIIIA

PERIODS (horizontal row) Counted from the top of the table down as Period 1, Period 2, etc. There are 7 (seven) periods in the periodic table The number of the period is the same as the number of energy levels the elements in that row possess

Stating Group and Period Number Identify the period number and the group number for the following elements: a) calcium b) tin a) Period 4, Group 2A b) Period 5, Group 4A Give the symbols of the elements that are represented by the following period and group numbers a) Period 3, Group 5A b) Period 6, Group 8A a) Phosphorus (P) b) Radon (Rn)

Metal - Conducts electricity/heat well - Forms cations - Forms Ionic bonds with non-metals - dense - lustrous and ductile and malleable - high melting and boiling points Non-metal - Conducts heat/electricity poorly - Forms anions - Forms Ionic bonds with metals - Forms Covalent bonds with non-metals - less dense - dull and brittle - low melting/boiling points Metalloids - act somewhere between metals and non-metals

Metals, Nonmetals, and Metalloids A heavy zigzag line (staircase) separates the metals (left) from the nonmetals (right) Elements that lie on either side exhibit properties of both = metalloids (sometimes called semi-metals) Hydrogen is the exception – it can behave as both but is generally classified as a nonmetal

Metals Shiny solids Ductile = can be shaped into wires Malleable = can be hammered into a flat sheet Good conductors of heat and electricity Usually melt at higher temperatures than nonmetals Solids at room temperature (except mercury which is a liquid)

Nonmetals Not very shiny Not very ductile Not very malleable Poor conductors of heat and electricity Typically have low melting points and low densities What are living organisms made of predominantly, metals or nonmetals?

Metalloids Located along heavy line Include B, Si, Ge, As, Sb, and Te Exhibit some properties that are typical of the metals and other properties characteristic of nonmetals Ex) better conductors of heat and electricity than nonmetals, but not as good as metals Can act as conductors or insulators = semiconductors

Classifying Elements as Metals and Nonmetals Using a periodic table, classify the following elements as metals or nonmetals. a) Na b) C c) Cl d) Cu a) M b) NM c) NM d) M Which of the following elements, nickel or nitrogen, would be a gas and a poor conductor of heat? Nitrogen

Classification of Groups Several groups in the periodic table have special names Alkali Metals group1 Alkaline Earth Metals group 2 Halogens group 17 Noble Gases group 18 Transition metals groups 3 to 12

Alkali Metals Soft Shiny Good conductors of heat and electricity Relatively low melting points React vigorously with water Form white products when combined with oxygen

Alkaline Earth Metals (aka Rare Earth Metals) Shiny Harder and more dense than the alkali metals Highly reactive, but Not as reactive as alkali metals Also have higher melting points and boiling points. Like the alkali metals, the alkaline metals are never found free in nature. The alkaline earth metals have two electrons in their outermost energy level, so they also form positive ions.

Halogens Typical non-metals 7th Group in the Periodic Table 'Halogens' means 'salt formers' Relatively low melting points and boiling points. They are all coloured non-metallic elements (the colour gets darker down the group) They are all poor conductors of heat and electricity When solid they are brittle and crumbly e.g. iodine.

Noble Gases Group 8 colorless gases extremely unreactive because their outermost energy level is full Because seldom found in combination with other elements they are called inert. All the noble gases are found in small amounts in the earth's atmosphere.

Transition Metals *Have properties similar to one another and to other metals, but their properties do not fit in with those of any other family. Most transition metals are excellent conductors of heat and electricity. Most have high melting points and are hard. Transition metals are much less reactive than the alkali and alkaline earth metals. Many transition metals combine chemically with oxygen to form compounds called oxides. Transition metals form compounds that are brightly colored.

Summary of The Periodic Table The periodic table is an arrangement of the elements by increasing atomic number Each vertical column contains a group of elements, which have similar properties A horizontal row of elements is called a period On the periodic table, the metals are located on the left of the heavy zig-zag line, the nonmetals are to the right, and metalloids are next to the zig-zag line. Quiz1 and Quiz 2

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