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The Periodic Table. Ch. 7 Sec 1. Standards. 8.3.f Students know how to use the periodic table to identify elements in simple compounds. 8.7.a Students know how to identify regions corresponding to metals, nonmetals, and inert gases.
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The Periodic Table Ch. 7 Sec 1
Standards • 8.3.f Students know how to use the periodic table to identify elements in simple compounds. • 8.7.a Students know how to identify regions corresponding to metals, nonmetals, and inert gases. • 8.7.b Students know each element has a specific number of protons in the nucleus (the atomic number) and each isotope of the element has a different but specific number of neutrons in the nucleus. • 8.7.c Students know substances can be classified by their properties, including their melting temperature, density, hardness, and thermal and electrical conductivity.
Vocabulary • Periodic • Period • Group • Periodic law
A. Arranging the Elements • Suppose that you are at a video store and all the videos are mixed together. How can you quickly find a comedy or an action movie? If the videos are not arranged in a pattern, you won’t know where to look!
Scientists in the early 1860’s had a similar problem… • Scientists knew the properties of more than 60 elements • They didn’t have a way to organize them • They looked for patterns • They used the element’s properties
B. Discovering a Pattern • Mendeleev discovered a pattern to the elements in 1869 • First, he wrote the names and properties of the elements on cards • Then, he played “chemical solitaire” with the cards • He arranged his cards by different properties, such as density, appearance, and melting point • He arranged the elements in order of increasing atomic mass. When he did, a pattern appeared
Pg. 194 Fig. 1 By playing “chemical solitaire” on long train rides, Mendeleev organized the elements according to their properties.
Periodic Properties of the Elements • Not just increasing atomic number, but other patterns, periodic patterns • Periodic means “happening at regular intervals.” • Can you name any? • Patterns repeated every seven elements…
Predicting Properties of Missing Elements • Pg. 195 Fig. 2 • This first try shows gaps • He predicted that elements that weren’t found yet would fill the gaps • By 1886, all the gaps were filled as predicted • Pg. 195 Table 1
C. Changing the Arrangement • A few elements discovered didn’t fit • Another scientist arranged them by protons, atomic number, and it fit • Next page…
The first “Periodic Table” included all of today’s elements. • True • False
________ means “happening at regular intervals.” • Period • Periodic • Group • Periodic Law
Elements on the periodic table are in arranged in order of • Increasing density • Decreasing density • Increasing atomic number • Decreasing atomic number
What are most of the elements in the periodic table? • Metals • Metalloids • Precious metals • Nonmetals
Activity: Vocab. • On the paper I give you: • For each vocabulary word: • Write the word • The definition • Draw a picture of the word • Write a meaningful, well thought out sentence using the word
D. Table and Classes of Elements • Studying the table may seem tough and you can get lost… • Elements classified by properties; metals, nonmetals, and metalloids. • The zigzag line can help tell which elements are metals, nonmetals, and metalloids.
Each square on the table includes an element’s name, chemical symbol, atomic number, and atomic mass. • Groups (families) are vertical • Periods are horizontal
Metals • Most elements are metals • Left of the zigzag line • Most metals are solid at room temperature, although Mercury isn’t
The elements in each vertical column on the periodic table usually have similar properties and are called a(n) • Period • Group • Element • Property
The elements to the right of the zigzag line on the periodic table are called • Metalloids • Conductors • Metals • Nonmetals
A horizontal row on the periodic table are called a(n) • Group • Family • Period • Atomic number
Which of the following is metalloid? • Fe • Se • Ge • Ga
Which of the following are all nonmetals? • K, Ca, Sc • Se, Br, Kr • V, Cr, Mn • As, Se, Br
Which of the following elements has 19 as its number of protons? • K • Kr • Fe • Cu
On the periodic table, the letter “C” for carbon is the • Atomic number • Atomic mass • Chemical symbol • Element’s name
The number at the top of the square on the periodic table is the • Atomic number • Element name • Atomic mass • Chemical symbol
Activity: Using the Table • Using the Periodic Table answer these questions • How many groups are there? Which direction do the groups go? • How many periods are there? Which direction do the periods go? • Name the element types in each of the three colored sections. • Name the state of matter in each of the three color of the symbols. • Which elements were out of order according to Mendeleev’s table?
Activity: Table to text • With a partner, write sentences of 10 elements using the symbol, atomic number, and atomic mass • Ex: The chemical symbol C stands for carbon, which has an atomic number of 6 and an atomic mass of 12.0. • Then read the sentences to each other
Most metals are • Solid at room temperature • Bad conductors of electricity • Dull • Not malleable
Nonmetals • Right of the zigzag line • More than half are gas at room temp • Many properties are opposite of metals • Metalloids • Border the zigzag line • Properties of metals and nonmetals • Pg. 199 Fig 4
E. Decoding the Periodic Table • To learn how to read the code…you need to know the symbols and numbers… • Chemical Symbols • For most, it has one or two letters • First letter capitalized, others lower case • In formulas, you can use the table to figure it out • CO2 + H2O -> C6H12O6 + 02 • HF + NaF ⇌ NaHF2
Periods • A period is a horizontal row of elements (from left to right) on the periodic table • Groups • A group is a vertical column of elements (from top to bottom) on the periodic table
Atomic Number • All elements follow periodic law • The periodic law states that the repeating chemical and physical properties of elements change periodically with the elements’ atomic numbers. • Properties change and repeat as the atomic numbers change
A _______ is a vertical column of elements (from top to bottom) on the periodic table • Period • Group • Atomic number • Chemical symbol
In each square on the periodic table, the number at the top is the • Atomic number • Element name • Atomic mass • Chemical symbol
Activity: Element Reports • You will work in pairs and use the computers to write a report about elements • Use PowerPoint or Word to make the report • Each group will choose two elements • Reports should include: • the name • Symbol • Atomic Number • atomic mass • classification • period number • other interesting facts and pictures you find