Focus Question: How are the Elements Arranged? Elements and Atoms 4-1 Mixtures and Solutions Unit
What are these items?• Describe as completely as possible what is in the two cups.• Describe what the two strips are made of.• What is this pencil lead made of?• What about the diamond in my ring?• My jewelry?
Elements and Compounds• There are two kinds of chemical substances in the world – Elements and Compounds• Elements = one kind of atom only• Compounds = two or more different kinds of atoms• Which substances on the board are Elements and which are Compounds?
Elements and Compounds• Each substance on our list is different from the others.• Formulas for water and carbon dioxide have two different kinds of atoms. That makes them compounds.• What other compounds have we worked with in science?• The rest of the substances on our list are elements • Each of them are made of different elements
Three important things to understand• A sample of an element is made out of one kind of atom only• Every element has its own kind of atom. Oxygen - oxygen atoms, Nitrogen - nitrogen atoms, Aluminum - aluminum atoms • Every element’s atom is different than every other element’s atom.• There are only 90 different kinds of atoms that occur naturally on Earth, so there are only 90 different elements on Earth as well.
Periodic Table of Elements• Placement of each element provides information about its chemical properties• Size - elements are ordered from smallest to largest• Read across row, then down to next row• Two rows dropped below for space
Navigating the Periodic Table• Work in pairs to place the atom disks on the corresponding elements on the Periodic Table.• What do you notice about the distribution of the atom disks?
Elements Checklist• The 90 elements found on Earth are listed in alphabetical order.• Read through the list and check the elements you know something about or have heard of.• Write a word on the line after the element to indicate how that element is used or what kind of substance it is found in.• Which ones do we know?
Homework• All matter is made of atoms.• 90 different atoms on Earth that things can be made of.• You, everything you own, everything you eat is made of elements.• How many elements can we find in the things we get at stores?• Bring in items from the Element Search list.• Read Organizing the Elements, pg 42- 47 and answer questions.
Vocabulary• Element - a sample of matter (a substance) composed of only one kind of atom• Chemical property of an element - how it reacts (or doesn’t react) with other elements• Compound - a combination of two or more different kinds of atoms that are chemically combined• Periodic table - a graphic display of the elements
Content• What is an element?• A substance that is made of only one kind of atom• What is a compound?• A substance made up of two or more different kinds of atoms• What is the periodic table?• A graphic display of the elements• Your questions?