BiologyBiology

Chapter 6Chapter 6

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AFDF0D811E is your code to get into the AFDF0D811E is your code to get into the book on line.book on line.

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Vocabulary wordsVocabulary words

MatterMatter ElementElement NucleusNucleus ProtonProton NeutronNeutron ElectronElectron Atomic numberAtomic number Mass numberMass number IsotopeIsotope ionion

Periodic TablePeriodic Table

Elements as Building BlocksElements as Building Blocks As you probably saw, the As you probably saw, the periodic tableperiodic table is is

organized like a big grid. The organized like a big grid. The elementselements are placed are placed in specific places because of the way they look in specific places because of the way they look and act. If you have ever looked at a grid, you and act. If you have ever looked at a grid, you know that there are rows (left to right) and know that there are rows (left to right) and columns (up and down). The periodic table has columns (up and down). The periodic table has rows and columns, too, and they each mean rows and columns, too, and they each mean something different. something different.

PeriodsPeriods

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You've got Your Periods...You've got Your Periods... Even though they skip some squares in between, all of Even though they skip some squares in between, all of

the rows go left to right. When you look at a periodic table, the rows go left to right. When you look at a periodic table, each of the rows is considered to be a different each of the rows is considered to be a different periodperiod (Get it? Like PERIODic table.). In the periodic table, (Get it? Like PERIODic table.). In the periodic table, elements have something in common if they are in the elements have something in common if they are in the same row. All of the elements in a period have the same same row. All of the elements in a period have the same number of number of atomic atomic orbitalsorbitals. Every element in the top row . Every element in the top row (the first period) has one orbital for its (the first period) has one orbital for its electronselectrons. All of the . All of the elements in the second row (the second period) have two elements in the second row (the second period) have two orbitals for their electrons. It goes down the periodic table orbitals for their electrons. It goes down the periodic table like that. At this time, the maximum number of electron like that. At this time, the maximum number of electron orbitals or electron shells for any element is seven. orbitals or electron shells for any element is seven.

GroupsGroups

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Group info.Group info.

.and Your Groups.and Your Groups Now you know about periods. The periodic table has a Now you know about periods. The periodic table has a

special name for its columns, too. When a column goes special name for its columns, too. When a column goes from top to bottom, it's called a from top to bottom, it's called a groupgroup. The elements in a . The elements in a group have the same number of electrons in their outer group have the same number of electrons in their outer orbital. Every element in the first column (group one) has orbital. Every element in the first column (group one) has one electron in its outer shell. Every element on the second one electron in its outer shell. Every element on the second column (group two) has two electrons in the outer shell. As column (group two) has two electrons in the outer shell. As you keep counting the columns, you'll know how many you keep counting the columns, you'll know how many electrons are in the outer shell. There are some exceptions electrons are in the outer shell. There are some exceptions to the order when you look at the to the order when you look at the transition elementstransition elements, but , but you get the general idea. you get the general idea.

Hydrogen and HeliumHydrogen and Helium

Hydrogen (H) and helium (He) are special elements. Hydrogen (H) and helium (He) are special elements. HydrogenHydrogen can have the talents and electrons of two can have the talents and electrons of two groups, one and seven. To scientists, hydrogen is groups, one and seven. To scientists, hydrogen is sometimes missing an electron, and sometimes it has an sometimes missing an electron, and sometimes it has an extra. extra. HeliumHelium is different from all of the other elements. It is different from all of the other elements. It can only have two electrons in its outer shell. Even though can only have two electrons in its outer shell. Even though it only has two, it is still grouped with elements that have it only has two, it is still grouped with elements that have eight (eight (inert gasesinert gases). ).

The elements in the center section are called transition The elements in the center section are called transition elements. They have special electron rules. elements. They have special electron rules.

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Wow: Wow: http://www.chem4kids.com/files/atom_intro.http://www.chem4kids.com/files/atom_intro.htmlhtml thank you Mr. Huff thank you Mr. Huff