Pure Substances, Mixtures and Solutions PowerPoint for week ending 9/25/15

Pure Substances A PURE SUBSTANCE is made of only one kind of material and has definite properties. Examples: elements (Hydrogen), molecules (Oxygen in the air we breathe-O2), compounds (water H2O)

Mixtures Examples: Salt and Pepper, Trail Mix, Lucky Charms A MIXTURE is a combination or more compounds or elements without a chemical reaction. Because there is no chemical reaction, the different compounds in the mixture can be separated. Examples: Salt and Pepper, Trail Mix, Lucky Charms

Solutions A SOLUTION is a mixture where the particles of two or more pure substances are mixed evenly. Examples: Kool-Aid, Sweet Tea

Half-Life Fission Fusion

Half-Life Half-life is the time it takes for half of the nuclei in a sample of the isotope to decay. When the decay occurs, the sample changes to another element. We can calculate the amount of a radioactive element that will be left if we know its half-life.

Fission The word fission means “to divide”. Nuclear fission is the process of splitting a nucleus into several smaller nuclei. This process creates a tremendous amount of energy! The word fission means “to divide”. Only large nuclei can undergo nuclear fission Ex) uranium and plutonium The products include: several individual neutrons in addition to the smaller nuclei.

Fusion The word fusion means “to fuse together”. In nuclear fusion, two nuclei with low masses are combined to form one nucleus of larger mass. This process creates even more energy than fission! The word fusion means “to fuse together”. Must be exposed to high temperatures in order for the positively charged particles to get close enough to fuse. Ex) The SUN!!

Quiz Pure Substances, Mixtures, Fission, Fusion 9/25/15

QUIZ 1) WHICH OF THE FOLLOWING DESCRIBES A PURE SUBSTANCE? AN ELEMENT, COMPOUND OR MOLECULE BONDED TOGETHER A MIXTURE A SOLUTION SALTWATER

QUIZ 2) WHICH OF THE FOLLOWING IS AN EXAMPLE OF A PURE SUBSTANCE? WATER (H2O) SALT WATER TRAIL MIX SUGAR WATER

QUIZ 3) THE HALF-LIFE OF RADON-222 IS 3.8 DAYS. HOW MUCH OF A 100g SAMPLE IS LEFT AFTER 15.2 DAYS?

QUIZ 4) THE HALF-LIFE OF COBALT-60 IS 5.26 YEARS. IF 50g ARE LEFT AFTER 15.8 YEARS, HOW MANY GRAMS WERE IN THE ORIGINAL SAMPLE?

QUIZ 5) What is fission? Two smaller nuclei fusing together One larger nucleus breaking into smaller nuclei Electrons fusing with other electrons Water breaking into hydrogen and oxygen

QUIZ 6) What is fusion? Two smaller nuclei fusing together One larger nucleus breaking into smaller nuclei Electrons fusing with other electrons Hydrogen and oxygen bonding to form water

QUIZ 7) Which of the following creates the most amount of energy? Fission Fusion Heating Freezing

QUIZ 8) Explain what must happen for fusion to occur. **THINK ABOUT THE PROTONS**

QUIZ 9) Which “side” are you on for the nuclear energy argument? Give two reasons for your chosen “side”.

Coloring the Periodic Table Families Some images are from www.chem4kids.com www.middleschoolscience.com 2008

Families on the Periodic Table Elements on the periodic table can be grouped into families based on their chemical properties. Each family has a specific name to differentiate it from the other families in the periodic table. Elements in each family react differently with other elements.

ALKALI METALS Group 1 Hydrogen is not a member, it is a non-metal 1 electron in the outer shell Soft and silvery metals Very reactive, esp. with water Conduct electricity Image: http://www.learner.org/interactives/periodic/groups2.html

ALKALINE EARTH METALS Group 2 2 electrons in the outer shell White and malleable Reactive, but less than Alkali metals Conduct electricity

TRANSITION METALS Groups in the middle Good conductors of heat and electricity. Some are used for jewelry. The transition metals are able to put up to 32 electrons in their second to last shell. Can bond with many elements in a variety of shapes.

BORON FAMILY Group 3 3 electrons in the outer shell Most are metals Boron is a metalloid

CARBON FAMILY Group 4 4 electrons in the outer shell Contains metals, metalloids, and a non-metal Carbon (C)

NITROGEN FAMILY Group 5 5 electrons in the outer shell Can share electrons to form compounds Contains metals, metalloids, and non-metals

OXYGEN FAMILY Group 6 6 electrons in the outer shell Contains metals, metalloids, and non-metals Reactive

Halogens Group 7 7 electrons in the outer shell All are non-metals Very reactive are often bonded with elements from Group 1

Noble Gases Group 8 Exist as gases Non-metals 8 electrons in the outer shell = Full Helium (He) has only 2 electrons in the outer shell = Full Not reactive with other elements (INERT)

Rare Earth Metals Some are Radioactive The rare earths are silver, silvery-white, or gray metals. Conduct electricity