Tuesday, November 29, 2011

In Science Class . . . Week of 11/28

5th Grade: This week, we started investigations in the solar system. Students worked with cards with each of the components of our solar system on them, including comets, planets, satellites, asteroids and the sun. On the back of each of these cards is important information about the object's mass, diameter, composition, distance from sun and temperatures. We worked on organizing them in order from the sun, and next week will work on other sorting skills. Key questions to ask:

  • What is the order of the planets? (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Pluto is now classified as a dwarf planet.)
  • What is the difference between the inner and outer planets? (Inner planets are rocky and solid, while outer planets are made of gas.)
  • What is the largest planet? (Jupiter) The smallest? (Mercury)
  • What planets have very high surface temperatures? (Those closest to the sun, though Venus is hotter than Mercury because it has an atmosphere that helps it retain heat.)
  • Why don't the earth and other objects fly off into outer space? (Because of the sun's gravitational pull)
  • Why do the moon and man-made satellites continue to orbit around the earth? (Because of gravitational pull of the earth.)
4th Grade: This week, we will review series and parallel circuits and began some exploration of electromagnets. Later in the week, we'll look at how the number of winds of the wire of an electromagnet affects it's strength. We'll also discuss the uses of electromagnets in engineering many of the gadgets we use every day!
  • What are the differences between parallel and series circuits? (Parallel circuits allow for multiple pathways of electricity, which results in more electricity going towards the bulb or motor. Series circuits require that multiple bulbs/motors share a pathway, which means the bulbs are dimmer or the motors go slower. For reference, the bulbs in your house are on a parallel circuit - they can be bright at the same time, and if one goes out, they don't all go out! By comparison, those old Christmas lights are on a series circuit where if one bulb goes out, none of them work. )
  • What is an electromagnet? (One can induce magnetism in an iron object by wrapping a wire around it and hooking it up to a electricity source. We used a iron needle-like thing hooked to a battery to pick up washers.)
  • What is the advantage of an electromagnet? What are they used for in every day life? (Electromagnets can be turned on and off, unlike permanent magnets. They are used in everything from doorbells to junk yards to many electronics.)

Wednesday, November 16, 2011

In Science Class . . . . Week of 11/14

4th Grade: This week, the 4th graders will be studying series and parallel circuits. They'll find that, in a series circuit, the light bulbs are dimmer because the two bulbs have to share one pathway of electricity. In a parallel circuit, the two lights are brighter because they each have their own pathway of electricity to the d-cell (battery). For example, in the older strings of Christmas lights, the bulbs are often on a series circuit. When one light bulb goes out, the whole string of lights does not work because the one pathway of electricity is not complete. By comparison, lights in your house are on a parallel circuit - there are many pathways of electricity that allow the lights to operate independently of each other.
  • How are parallel and series circuits similar and different? (Both are circuits that can carry electricity. A parallel circuit allows for multiple paths of electricity, while a series circuit just has one)
After Thanksgiving break, the 4th graders will be studying electromagnets. I hope to wrap up this unit on magnetism and electricity by mid Dec.

5th Grade: This week, the students will be taking a quiz on mixtures, solutions, chemical reactions, periodic table, etc on Friday. Today (Wed) we will complete a study guide that has all the required information. This will go home and students can study at home. The quiz will also be open-notebook so students can use their notebook as a resource, too.

After Thanksgiving break, we will be starting our 5th Grade Earth Science unit that includes the water cycle, solar system and weather.

Thursday, November 10, 2011

In Science Class . . . Week of 11/7

4th Grade: The 4th graders continued their exploration of electricity by finding out what materials conduct (carry) electricity and which do not. The students used a circuit board with a motor hooked up to a d-cell and put various objects between the wires. We also walked around the classroom to see which materials in the room would complete the circuit and turn the motor on.
  • Which materials conduct electricity? (All metals - copper, brass, steel, iron, aluminum)
  • How is this different from what materials are magnetic? (Only iron and steel objects can become magnets)
  • What materials did not carry electricity? (Cardboard, paper, plastic, wood, fabric)
5th Grade: We had an exciting week! On Monday, students investigated properties of materials. We found that, unlike plastic or wood, metals can conduct (or carry) heat and electricity. We used the materials to complete a circuit and found that all metals will allow the motor to go on. We also put strips of material in a container with shallow hot water. The tops of the strips had butter on them. We watched as the copper and aluminum strips had butter that melted FAST! Steel and brass were slower. Heat was not conducted with the plastic and wood strips.

On Wednesday, we had visiting graduate students from the Cal chemistry department teach a lesson about chemical reactions and glow in the dark science! Students watched as they mixed two chemicals together to produce gas and light in a reaction similar to that which happens in a glow stick. Next, students mixed water, Elmer's glue and Borax to make a putty material. The material also had a little glow-in-the-dark paint which made it fun! Families, this stuff is not toxic, but please don't let your kids eat it! It will last for quite a while. If it starts to dry out, just add a little water. For optimum glow, re-charge the putty by exposing it to light.
  • What properties make metals different than other types of elements on the periodic table? (Metals conduct heat and electricity much better than other elements. They also are mostly solid at room temperature and won't break when hammered into thin sheets. These properties make them extremely useful for building things)
  • In the two experiments with the grad students, how did you know a chemical reaction occurred? (In the first one, gas and light were produced. In the second reaction in our zip bags, the material turned from a liquid to a solid with the addition of the liquid Borax solution. This unexpected phase change is often indicative of a chemical reaction.)
PLEASE: If you have any old food or household packages or bags (that aren't gross) that have the ingredients listed on them, send them in with your student for class on Wednesday, 11/16. Anything would be great - chip bags, cereal boxes, bread bags, toothpaste boxes, soda cans, etc. We'll be looking for elements on the package. Cereals are especially fun since there are often minerals added for nutritional value like iron, zinc etc. Thanks!

Friday, November 4, 2011

In Science Class . . . Week of 10/31

Happy Halloween! Here's what we've been up to in class:

4th Grade: The students this week continued their exploration of magnetism and electricity using some mini-investigations. Stations included
  • Hand crank generator that produced power for light bulbs (one energy efficient and one regular)
  • A energy ball (called a UFO ball) that lights up and makes noise when you make a complete circuit with your body and it's metal pieces
  • A basic electromagnet that can pick up small washers
  • A magnetic generator that produces electricity by sliding a magnet through a tube wrapped with wire
  • Review of poles using doughnut magnets
  • A basic circuit with d-cell and light bulb
It's been really fun! Ms. Sinai's class also investigated conductors and insulators by putting objects into a circuit hooked to a motor. If the object could carry the electricity, then the motor ran. If not, the object was an insulator and the motor would not go on. Conductors included all metal objects - nails, paper clips, chair leg, washers, etc. The rest of the 4th grades will do this next week!

5th Grade: Students this week completed their presentations on a group of the periodic table. Next week, we'll look closely at the properties of metals and do some other fun chemical reactions!