1. Grade 6 Science Midterm Help Session
Ms. Amanda

2. Elements A pure substance containing only one kind of atom.
An element is always uniform all the way through (homogeneous)
An element cannot be separated into simpler materials (except during nuclear reactions).
Over 100 existing elements are listed and classified on the periodic table.

3. Compounds A pure substance containing two or more kinds of element.
The atoms are chemically combined in some way. Often times (but not always) they come together to form groups of atoms called molecules.
A compound is always homogeneous (uniform).
Compounds cannot be separated by physical means. Separating compounds requires a chemical reaction.
The properties of a compound are usually different than the properties of the elements in contains.

4. Mixtures Two or more elements or compounds NOT chemically combined.
No reaction between substances.
Mixtures can be uniform (called homogeneous) and are known as solutions.
Mixtures can also be non-uniform (called heterogeneous).
Mixtures can be separated into their components by chemical or physical means.
The properties of a mixture are similar to the properties of its components.

5. Elements, Compounds, and Mixtures
Trail mix
Iron
A dog
Granite (rock)
Carbon
Magnesium
Table Salt (NaCl)
Sugar
Pepsi
Coffee
Water (H2O)
Helium
Beryllium
Carbon Dioxide (CO2)

6. Heterogeneous or Homogeneous
A sheep
Fruit Juice
Salad
Kool-Aid
Coca Cola
Coffee with milk
Sugar water
A backpack
Tap water
Pasta salad

8. Variations of atoms Gain or lose a proton – new element
Gain or lose a neutron – isotope
Gain or lose an electron – ion
Example question: If an atom has 7 protons, 8 neutrons, and 7 electrons, what type of atom is it?

9. Ions
Example questions: If an atom has 5 protons, 5 neutrons, and 6 electrons, what is the charge? If an atom has 15 protons, 15 neutrons, and 18 electrons, what is the charge? If an atom has 12 protons, 12 neutrons, and 12 electrons, what is the charge?

10. Atom models (Lithium, atomic number 3)
Proton
Neutron
Electons

11. Density Calculations D=m/v
What is the density of a solid with a mass of 90 grams and a volume of 45 cm cubed? What is the density of a solid with a mass of 20 grams and a volume of cm cubed?

12. Energy Transfomations
Draw a picture showing the energy transformations that are happening when a you use your muscles to stretch a sling shot which then moves up in the air, and falls back down to the ground, speeding up.

13. Match the Energy Transformation
A microwave
A bicycle stopping
A cell phone
Photosynthesis
A space heater
A ball thrown in the air
A nuclear power plant
A gasoline powered car
Radiant  Chemical Potential
Electric  Thermal
Radiant  Sound
Electrical  Radiant  Thermal
Mechanical  Thermal
Nuclear  Thermal  Electrical
Chemical  Mechanical
Kinetic  Graviational PE  Kinetic

14. Advantages and disadvantages
Types of Non-renewable energy
Uranium (nuclear)
Fossil Fuels
Types of Renewable energy:
Solar
Wind
Water (hydroelectric)
Biomass
Geothermal

15. What renewable energy resources would be best to use in Kuwait, and why?
Can it be used in Kuwait?
Why or why not?
Solar
Yes
There are many sunny days in Kuwait. Solar panels could be put in the desert.
Wind
There are many windy days. Wind farms could be put in the desert.
Water/Hydroelectric No
We have no large rivers. There are not large tidal differences in the Arabian gulf.
Geothermal
Kuwait is not in a tectonically active area (no volcanoes or hot springs)
Biomass
Some
We could burn trash/waste. We don’t have many trees to burn.

16. Preparing for an exam Study a little bit each day.
Answer all questions in the study guide.
Use vocabulary flash cards, or have someone quiz you!
Get plenty of sleep the night of the exam!
Eat a healthy breakfast
Stay hydrated (but don’t drink too much water right before the exam!)

17. During the exam Relax! Take your time, don’t rush!
On multiple choice: eliminate the answers you know are wrong, and choose the best remaining answer.
If you don’t know the answer, move on to the next question and go back at the end.
Attempt to answer every question. There is no penalty for a wrong answer!
Check your answers when you finish the exam.
BUT…your first guess is usually more likely to be right! Be careful if you decide to change your answers.