1 Explain the difference between an element and a compound. What method would I use to separate a salt water solution? HOMEWORK ON YOUR DESK

Complete the Elements, Molecules, and Compounds worksheet as you visit the following 4 slides. 1 What is the difference between these 2 molecule pictures ?

Atoms: The Basic Building Blocks of All Matter Why does this picture represent the phrase above? Where does the word “Atom” come from? It’s a Greek word that means “un-cuttable”. Imagine taking a piece of gold and cutting it into tiny pieces until you couldn’t cut it into any more pieces….you have reached the smallest part of the gold. Gold is an element that is made of just gold atoms. Well, atoms are very, very tiny. Too small to even see with our eyes. But, atoms are what makes everything in our world. When the same kind of atom combines until you can see that substance, that substance is called an element.

How are atoms and molecules related? The matter you see is made of parts you can’t see—atoms! When the same or different atoms combine and bond together, they make molecules. The force that holds atoms together is called a chemical bond. You can think of chemical bonds as the “glue” that makes atoms stick together. The types of atoms and how they are joined by the bonds determine the properties of that substance.

When atoms combine and bond together, they make molecules. For example: When 2 oxygen atoms combine they form an oxygen molecule like in the air we breath. When 2 hydrogen atoms combine with 1 oxygen atom, it makes a molecule also----a water molecule. All molecules are held together by chemical bonds, like glue. 2 hydrogen atoms + 1 oxygen atom = 1 water molecule (The oxygen in the air we breath) 1 oxygen molecule + = 1 oxygen atom

Now, before they combined, think about the properties of hydrogen and oxygen atoms. Hydrogen and oxygen are invisible gases. However, when they combined and bonded together, they lost all their old properties and gained new ones: they made a clear liquid with no odor. H O H H O

Elements – substances that are made of only one type of atom. For example – hydrogen and oxygen Compounds – molecules made from two or more different atoms combined chemically to make a new substance. For example water – H2O H H O H **Add these definitions (with examples & pictures) to your vocabulary section! OO

Have Mrs. Kelly check your worksheet & vocabulary page BEFORE going past this slide!!!!

Elements, Molecules, Compounds Explanation Activity 1.How does the picture of the bricks show that atoms are the basic building blocks of all matter? ____________________________________________________________________________ ____________________________________________________________________________ 2. What is an element? __________________________________________________________________________ 3. What is a molecule made of? ____________________________________________________________________________ 4. What holds atoms in a molecule together? ____________________________________________________________________________ 5. When 2 hydrogen atoms combine with 1 oxygen atom, it makes a _______________ molecule. 6. Hydrogen and oxygen are invisible _________ and hydrogen is reactive. However, when they combined and bonded together, they lost all their old properties and gained new ones: they made a ________________________ with no odor. Bricks are put together to build walls & buildings just like atoms are put together to build all matter. When the same kind of atom combines until you can see that substance Molecules are made when the same or different atoms combine and bond together. Chemical bond water gases clear liquid

Matter Molecules Elements – Substances made from only one type of atom Compounds – Two or more different types of atoms combined chemically to make a new substance.

If matter were like a sentence… Mmmm, my lunch was good! The whole sentence is like the matter. A single word is like a molecule. Why is “Mmmm” like an element? Why is “lunch” like a compound? One single letter is like an atom. Challenge: Answer in NOTES SECTION of binder. 1. What might the whole alphabet represent? 2. What might a paragraph represent? 3. What might the punctuation and spaces represent? Periodic table A big mixture of substances

When elements combine to form a compound, their properties change…. For example: Hydrogen + Oxygen = Water (explosive gas) (clear gas) (clear liquid)

Follow directions on the Modeling Elements & Compounds Worksheet

Conclusion Questions: 1.What made your models “compounds”? 2.Why couldn’t you make a molecule model with only one bolt or one nut? 3.Which of the materials could represent and “atom”? 4. What is the difference between an atom & a molecule? 5. What is the difference between an element and a compound? They all had 2 or more different kinds of parts hooked together Because a molecule has to have 2 or more atoms, not just one atom. All of the parts when they are NOT hooked together with anything else. An element only has one kind of atom and a compound has 2 or more different kinds of atoms or elements chemically bonded together. A molecule is made of 2 or more atoms chemically bonded together.

BrainPOP | Compounds and Mixtures