elements, compounds and mixtures aim what are compounds and how are compounds different from...
TRANSCRIPT
Elements, Compounds and Mixtures
Aim
What are compounds and how are compounds different from elements?
What are compounds?
• Do Now: Use your periodic table to answer the following questions.– Most of the elements on the periodic table fall
into which of the 3 main groups?
– Name the six elements that are classified as metalloids.
– Where on the periodic table are most non-metals found?
What are compounds?
• If elements are the simplest substances made up of only on type of atom. Compounds are the second simplest.
• Compounds are made of the atoms of 2 or more elements bonded together
What are compounds?
• Compounds: are pure substances that are made of two or more elements that are chemically bonded or combined.
O
H H
O OC
Chemical Bonds
What are compounds?
• Oxygen and Hydrogen are elements.
• When they chemically combine the elements H and O can form the compound Di-hydrogen Oxide or H2O.
O O H H
O
H H
What are compounds?
• Carbon and Oxygen are also elements.
• When Carbon and Oxygen chemically combine they can form the compound Carbon Dioxide or CO2.
O OC
O OC
What are compounds?
• Carbon Dioxide and Di-hydrogen Oxide (water) examples of simple compounds but there are more complex ones.
O
H H
O OC
What are compounds?
• Compound, like elements, have their own physical and chemical properties. These properties are different from the elements that make them.
Na Na Cl Cl Na Cl
The element Na (sodium) is a silvery white metal that reacts violently with water
The Element Cl (chlorine) is a poisonous greenish yellow gas
The Compound NaCl (sodium chloride) or table salt is a white solid that dissolves easily in water and is safe to eat
What are compounds?
• Compounds have specific recipes or chemical formulas that tell what elements are found in them and how many of each element is present.
O
H H
O OC
Water is made of two hydrogen atoms and one oxygen atom.
Water’s chemical formula is H2O
Carbon Dioxide is made of one Carbon atom and two oxygen atoms.
Carbon Dioxide’s chemical formula is CO2
Elements, Compounds and Mixtures
Aim
What are compounds and how are compounds different from elements?
What are compounds?
• Do Now: Using the following chemical formulas tell me what elements and how many atoms of each are found in the compound.
– H2SO4
– NH3
– AgNO3
– C6H12O6
– CaCl2
– NaOCl
– H3PO4
– Mg(SO4)2
• Molecule: The smallest unit of a compound that still retains all the physical and chemical properties of the compound
• A molecule is to a compound as an atom is to a element.
Elements, Compounds and Mixtures
Aim
What are compound?
How do you use a molecular bonding kit?
What are compounds?
• Do Now: Copy and answer– What is a molecule?
– How is a molecule similar to an atom?
– How is a molecule different from an atom
What are compounds?
• Do Now: Using the following chemical formulas tell me what elements and how many atoms of each are found in the compound.
– H2SO4
– NH3
– AgNO3
– C6H12O6
– CaCl2
– NaOCl
– H3PO4
– Mg(SO4)2
What are compounds?
• You can have completely different compounds that are made of the same exact elements if the numbers are not the same.
O
H H
O
H
H
O
H2O H2O2
Both of these compounds are made of oxygen and hydrogen. The H2O is water that you can drink. H2O2 is hydrogen peroxide and bubbles when you poor it on cuts. Its not a good idea to drink peroxide, it will make you throw up.
What are compounds?
• You can have completely different compounds that are made of the same exact elements if the numbers are not the same.
C
H H
C
H
H
C
CH4C2H4
Both of these compounds are made of Carbon and hydrogen.
The CH4 is methane. C2H4 is Ethene.
H HH
H
Using your molecular bonding kit?
• My Expectations– You will take care of your bonding kits. No
throwing the model elements or molecules.
– Pay attention what you are supposed to be doing.
– Do not just attach a bunch of elements together and then ask me, “Mr. Gantt, what is this?”
What color represents these elements?
• Carbon = has 4 holes
• Hydrogen = has 1 hole
• Oxygen = has 2 holes
• Nitrogen = has 3 holes
• The Halogens = has one hole
What are compounds?
• Compounds can be broken down through chemical means into the component elements.
• Two water molecules break down to form oxygen and hydrogen
O
H H
O
H H O O
H
H
H
H
What are compounds?
• Compounds can also be broken down into simpler compounds before being broken down in to elements
C
CC
C
C
COH
O
HH
H
OH
OH
OH O H
H
H
H
H
O
O
C CO
H H
OH H
C
CO
O
C C