Science is for Kids

HS-PS1-7:   Use mathematical representations to support the claim that atoms, and therefore mass,  are conserved during a chemical reaction. PS1-7 Evidence Statements The video below discusses the decomposition reaction of hydrogen peroxide and uses a balanced chemical equation and structural formulas to explain why the number of atoms is conserved in a chemical reaction. An experiment to help teach the concept of conservation of mass can be found here .

I was in a holiday kind of mood when I created this video.  The video captures a demonstration of a reaction of copper wire with a solution of silver nitrate which produced some beautiful silver crystals.  I think they look like snow flakes! The science behind this experiment is explained in this second video which gives a more in depth discussion of what happens during this oxidation-reduction chemical reaction. .

HS-PS2-5:  Plan and conduct an investigation to provide evidence that an electric current can produce a magnetic field and that a changing magnetic field can produce an electric current. HS-PS2-5 Evidence Statements The NGSS performance expectations are basically asking that students re-create the experiments of Michael Faraday.  In 1831, Faraday discovered the relationship between electricity and magnetism.  His experiments showed that electric currents could be manipulated to create magnetic fields and magnetic fields could be manipulated to create electric currents. I recently had my students compete in an engineering challenge as they worked towards meeting this learning standard.  The students really enjoyed having the opportunity to explore the topics of electricity and magnetism, design and build their electromagnets, test them and then finally compete. Students were allowed to use the following materials.  Students were allowed to request add...

HS-PS2-6:   Communicate scientific and technical information about why the molecular-level structure is important in the functioning of designed materials. PS2-6 Evidence Statements I introduced this topic to students by showing them a short video about gecko adhesive ( synthetic setae ).  Geckos feet are super-sticky due to numerous Van der Waals forces that form between the tiny endings of hairs that are found under their feet and whatever surface they are climbing on.  After the video we discussed the importance of molecular level interactions for the designed materials shown in the video.  Video options include the Weird Connections Episode " How Sticky is Your Gecko? ",  the segment about gecko adhesive from Nova's " Making Stuff Smarter " or  " Bio-Inspiration:Nature as Muse " from KQED-Quest. By Bjørn Christian Tørrissen - Own work by uploader, http://bjornfree.com/galleries.html, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?c...

This video shows a number of paramecium feeding on some algae.  Paramecium are single celled organisms called protozoans which are common in pond water. Paramecium use tiny hair-like structures called cilia in order to move.  Imagine a tiny boat with many oars moving in unison. Several other species of protists can be seen in this video. The video was shot with a hand-held HD camera using a cell phone mount created using a 3D printer with plans from Thingiverse .

HS-LS4-3 :  Apply concepts of statistics and probability to support explanations that organisms with an advantageous heritable trait tend to increase in proportion to organisms lacking this trait. HHMI BioInteractive video about the Rock Pocket mouse of the American southwest is a great example of how natural selection can cause evolutionary change.   Follow the link below for supporting documents for a classroom activity to support student learning of this topic. Developing an Explanation for Mouse Fur Color Another activity I've used to help students learn this concept is the Evodot simulation created by Jon Herron. Evodot Materials

HS-PS1-1 :   Use the periodic table as a model to predict the relative properties of elements based on patterns of electrons in the outermost energy levels of atoms. This video gives a quick summary of how to determine the number of valence electrons in the representative elements.  These are the elements found in the two left-most columns (below H and Be) and the six right most columns (below B, C, N, O, F and He).   Many properties of the elements can be predicted once you know how many valence electrons an atom possesses.  Elements in the same vertical column (H, Li, Na, K...) will have the same number of valence electrons which means that they will have similar chemical properties. One exception to this pattern is found in the Noble gases.  Helium has only two valence electrons while the other Noble gases contain eight.  

One of the really important  HS-LS2-5 performance expectations  is that students know the inputs and outputs of cellular respiration.  The video below shows a lab I've used for years with my biology students to teach this concept. The word equation for cellular respiration is summarized below. glucose (sugar)  +  oxygen   ->   carbon dioxide  +  water   Students perform the experiment using yeast and apple juice.  I have also used sugar water or solutions of different sugars.  The three trials the students typically do include... 1. warm water 2. room temperature water 3. cold water The lab also provides an opportunity to review or introduce factors can affect the speed of a chemical reaction ( HS-PS1-5 )

One of the really important HS-LS2-5 performance expectations is that students know the inputs and outputs of photosynthesis.  The video below shows a lab I've used for years with my biology students to teach this concept. The word equation for photosynthesis is summarized below. carbon dioxide  +  water  +  light  ->  glucose (sugar)  +  oxygen Students test plants (anarcharis or elodea) in three different types of water. 1. tap water = medium CO2 2. tap water boiled one day before the lab = low CO2 3. tap water with added baking soda = high CO2 The lab also provides an opportunity to introduce (or review) the concept of a limiting reactant since the level of carbon dioxide determines how much oxygen the plants will make as they carry out the light reaction of photosynthesis.

The leaf cutter ants in this video are carrying leaf pieces back to the fungus garden in their colony.  The ants harvest leaves in order to grow a fungus which is eaten by the ant larvae. The relationship between the fungus and the ant is an example of mutualism .  The ant benefits by being able to grow food for their offspring, and the fungus benefits because the ants feed the fungus and keep it free of mold and other pests.

This video talks about how osmosis causes changes in water levels inside of cells and helps us better understand the reason why humans can't drink salt water.   The Rime of the Ancient Mariner - Samuel Taylor Coleridge "Water, water, everywhere, And all the boards did shrink; Water, water, everywhere, Nor any drop to drink." Osmosis is the movement of water into or out of cells.  Salt water actually causes cells to lose water.  So if you were to drink too much salt water, you could actually die from dehydration. Read more about this from NOAA .

NGSS HS-PS3-3 :  Design, build, and refine a device that works within given constraints to covert one form of energy into another form of energy. For a number of years I taught a 9th grade physical science course that included a unit about engineering.  The final project of the unit had students designing, building, and testing trebuchets.  The students would compete to see which group could launch a projectile the greatest distance.  The competition could be ramped up by adding in an accuracy component as well. Students learned that the counterweight possesses gravitational potential energy which is converted to kinetic energy when the counterweight falls.  The dropping counterweight makes the throwing arm whip around to throw a projectile. This activity takes 2-3 class periods.  When I have had to complete this activity in fewer class period I pre-make the throwing arm and we would just switch it from one build to the next during testing.  If...

The capybara is the world's largest rodent.  They typically weight between 80-150 pounds, This video was filmed in Peru during the summer of 2010.  The footage was shot in the evening from a boat on the Tambopata River.  A group of capybara can be seen feeding on the banks of the river.  Capybara life almost everywhere in South America with Chile being the exception.

The video in this post takes a look at the molecular level explanation for why we write balanced chemical equations.  It comes down to understanding the Law of Conservation of Mass. Simply put, this law says that mass (matter) can't be created and it can't be destroyed in a chemical process.  Though matter can be created/destroyed in a nuclear process, that is a discussion for a future post. This video supports learning of NGSS HS-PS1-7.

- I really like this simulation for illustrating how static electricity works.  Try doing this with the sim. 1. Choose a single balloon 2. Grab the balloon with the mouse and then rub it on the sweater to charge the balloon. 3. Drag the balloon a small distance from the sweater and release it. 4. Drag the balloon close to the wall and notice what happens to charges in the wall. 5. Release the balloon close to the wall and see what happens. Play around with the sim and see what other things you can discover!

This video uses the Flash Animation " DNA Workshop " from PBS to illustrate the central dogma of molecular biology.  The video supports NGSS HS-LS1-1 . The central dogma explains how stored genetic information (genes) is retrieved and used by cells to produce proteins that are responsible for an organisms traits.  It can be summarized as follows: Attribution:  Dhorspool at en.wikipedia [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons

This video shows a classic lab examining the effect of concentration of reactants on the rate of a chemical reaction.  This video supports NGSS HS-PS1-5 . In this experiment solutions of sodium thiosulfate and hydrochloric acid are combined in a beaker.  The reaction produces a precipitate which eventually makes the liquid turn cloudy.  The reaction beaker is placed over a piece of paper with a letter "X" printed on it.  The reaction is said to have gone to completion when the "X" can no longer be seen through the liquid in the beaker. I have used this video as a warm up or as a flipped lesson which has students make observations, record data about the reaction time for the trials, create a graph and form a conclusion about the effect concentration has on the speed of a chemical reaction. This lab was originally published by Flinn Scientific as a Chem Fax!  Use this link to see the full description of the experiment.

HS-LS1-4:  Use a model to illustrate the role of cellular division (mitosis) and differentiation in producing and maintaining complex organisms. The video shown below was filmed using a hand-held HD camera mounted on the microscope eyepiece.  The video can be used to have students identify cells in different phases of the cell cycle.  

NGSS  HS-PS2-4 :  Use mathematical representations of Newton’s Law of Gravitation and Coulomb’s Law to describe and predict the gravitational and electrostatic forces between objects. [Clarification Statement: Emphasis is on both quantitative and conceptual descriptions of gravitational and electric fields.] A demonstration like the one shown in the video can spark dialogue by students to discuss how the gravitational force and electric forces compare.

NGSS HS-PS2-4 :  Use mathematical representations of Newton’s Law of Gravitation and Coulomb’s Law to describe and predict the gravitational and electrostatic forces between objects. Class started by trying to identify Cause and Effect relationships in the video below. Our next activity was an in class demonstration using a balloon, cloth and small pieces of paper.  The goal of the demo was to jump start thinking about how gravity and electrostatic forces can be compared to each other. Students completed a jig-saw activity to compile notes for Newton's Law of Gravitation and Coulomb's Law. I took pictures for each class and will share in their stream on Google Classroom.