Science is for Kids

To understand the evidence that the universe is getting larger, we need to understand the Doppler effect.  This is the reason why a siren from a police car or fire truck has a higher pitch as it is approaching and a lower pitch when it is traveling away from us. The two images below are really useful in trying to better understand the Doppler effect. The first image has a stationary red dot which is giving off waves, which is shown by the concentric blue circles.  The wavelengths of the waves being given off are represented by the distance between the concentric blue circles.  The waves would appear the same to four observers each located at the corners of the square area.  The second image shows waves being produced by a moving object.  In this case, the waves would appear to be different to observers on the right or left side of the square area.  Observers on the left side would observe waves that are stretched out because the object giving off ...

HS-PS4-5. Communicate technical information about how some technological devices use the principles of wave behavior and wave interactions with matter to transmit and capture information and energy.* [Clarification Statement: Examples could include solar cells capturing light and converting it to electricity; medical imaging; and communications technology.] HS-PS4-5. Evidence Statements This performance expectation has students communicating technical information about two devices using varying formats (textual,  graphical, oral and mathematical are listed in NGSS evidence statements.  I'm having my students research two devices (one that relies on the photoelectric effect, a second that depends on wave properties) and then create a screencast video using text, images and narration to teach their classmates about the device they selected. Devices that depend on the Photoelectric Effect: Photovoltaic cells (solar panels) Photocopiers Charge coupled...

A thermal decomposition reaction occurs when heat is applied to a compound causing it to decompose (break down) into multiple different chemical substances. An example is when baking soda (sodium bicarbonate) is heated 2 N a H C O 3 ( s ) → C O 2 ( g ) + H 2 O ( g ) + N a 2 C O 3 ( s ) Here is a video discussion of this reaction... I hope this was helpful!

This video shows a sample of cesium-137 being tested for emission of radiation.  Nuclei of cesium-137 isotopes are unstable and will undergo a process of radioactive decay to form more stable isotopes.  Cesium-137 is formed during fission reactions of uranium-235 in nuclear power plants and nuclear weapons. The equation that describes the radioactive decay of cesium is shown below.  The conversion of a neutron (from the cesium nucleus) to a proton causes the atomic number to increase from 55 to 56.  This leads to the formation of barium-137.  It's important to notice that the mass number stays the same in examples of beta decay. 137 Cs → 137 Ba + 0 e 55 56 -1

This video shows a chromatography experiment used to separate the different color pigments that are found in a black wet erase marker. This is an experiment that could easily be done at home.  Paper towel could be used instead of the chromatography paper I used to make this video.  You just need to use paper that is absorbent. It would also be fun to try this experiment using different types of markers or pens.  You could also try different liquids, rubbing alcohol would be an interesting choice. NGSS Connection: HS-LS1-1 3.Reasoning a. Students use reasoning to connect evidence, along with the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future, to construct the explanation. Students describe* the following chain of reasoning in their explanation iii. Proper function of many proteins is necessary for the proper functioning of the cells. I have used this...

HS-PS1-2:   Construct and revise an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties. This video covers important trends of the periodic table.  Topics include; reactivity, ionization energy, successive ionization energy, atomic radius, ionic radius, electron affinity, and electronegativity.

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 .