Young Scientists Club

The Young Scientists Club is a science enrichment program for elementary school children. In 2022-2023, it is being held as a weekly before-school club for 2nd and 3rd graders at Carmel Creek Elementary. During club meetings, students participate in hands-on interactive activities that demonstrate key scientific concepts. The club is run by Prof. Elena Koslover, with the aid of graduate students and postdocs from the UCSD physics department, parent volunteers, and volunteer scientists from the local community. It is funded as an outreach activity through a grant from the National Science Foundation. There is no cost to participate.

If you are a parent or scientist and would like to help organize, create, or run the YSC activities, please contact Lena Koslover. If your child is attending the current session, we need some parent volunteers to help supervise. Please contact Lena Koslover for a link to the sign-up sheet.

If you participated in Winter 2023 YSC, please fill out this Survey with your child.

(The survey results are crucial to maintain NSF support to keep the club going in future quarters. The survey should take about 10 min to fill out.)

Activity Worksheets: Spring 2023, Chemistry and Biochemistry

Separating Mixtures

Purifying components with physical processes.

Students will make a mixture of rice, sand, iron filings, and salt, measuring the amount put in by weight or volume. They will then use different laboratory processes (filtration, dissolution, magnetic extraction) to separate out the individual components and will measure the amount they recover. We will discuss how mixtures are made without breaking molecular bonds, so that the mixed substances can be extracted again without chemical reactions.

Activity dates: 4/13/2023

(BFSU connection: lessons A9, A14)

Worksheet (student version)
Worksheet (teacher version)

Activity Worksheets: Winter 2023, Matter and Fluids

Surface Tension

Exploring the effect of surfactants on surface tension.

Students observe how surface tension can hold a large drop of water together and how the effects of surface tension are reduced by the addition of soap. They also experiment "popping" the surface layer of water: making currents by forming a sufrace tension gradient. These currents are used to make tie-dye patterns in milk.

Activity dates: 3/9/2023, 4/23/2020

pdf worksheet
Required equipment:

Diffusion in Fluids

Spreading through Random Walks and Density Gradients

Students will run simulations (rolling dice) to demonstrate how the random jiggling of molecules in a solution leads to diffusion: the spreading of particles from high concentration to low concentration regions. By comparing transit times, they will see that diffusion across longer distances becomes very slow. We will also note that density or gradients can allow for faster spreading as solute molecules push each other out of a dense region. By watching the movement of colored dye away from dissolving skittles, students will observe how solute molecules spread out rapidly from a region of high density and then mix much slower by random-walk diffusion once the density gradient is gone.

Activity dates: 3/2/2023, 11/18/2020

(BFSU connection: lesson A11)

pdf worksheet
Alternate worksheet from 2020, covering diffusion and mixing in active fluids.

Fluid Viscosity and Drag

How Fluids Resist Flow

Students will buld a simple viscometer and use it to compare the flow rates and viscosities of different common fluids. They will then gain first-hand experience with viscous drag, by pulling a paperclip through fluids with a weak magnet at different speeds. Large drag forces due to fast speeds or high viscosities will rip the paperclip off the magnet. The maximum achievable speed can be compared among the fluids and will vary according to their measured viscosities.

Activity dates: 2/16/2023, 5/14/2022

pdf worksheet

Float versus Sink

Density of fluids

Students will measure densities of common fluids and learn that objects with lower density than the surrounding fluid will float. They will make a density column with three fluids and several common objects, predicting the order of the layers and the location where each object floats. They will then make their own "lava-lamps" with floating gas bubbles and sinking water droplets in a tube of oil, powered by an acid-base reaction.

Activity dates: 2/9/2023, 4/23/2022

(BFSU connection: lesson A15)

pdf worksheet

Density of Materials

Measuring mass, volume, and density

Students will learn about the concept of density as the mass per unit volume of an object. We will identify the material that pennies and dimes are made off by comparing them to pure metals. We will also compare densities of glass, plastic, metal, and rock and identify the true nature of a seemingly `golden' rock, a la Archimedes. This activity will introduce students to the use of scales and graduated cylinders, and to the notion of measurement precision and error.

Activity dates: 2/2/2023, 4/23/2022

(BFSU connection: lesson A15)

pdf worksheet

longer version worksheet (from 2022)

Gasses: Pressure and Volume

Pushing around air and blowing up balloons

In this activity, students demonstrate that air takes up space by using a cup as a diving bell. We find two different ways of blowing up a balloon without touching it, by increasing pressure or decreasing it through suction. The relationship between volume and pressure is applied to build a simple model of our lungs, where increasing the volume of a container (chest cavity) lowers the pressure and brings in air from the outside.

Activity dates: 1/26/2023

(BFSU connection: lesson A3, A6)

pdf worksheet

States of Matter

Solid, fluid, and in between

Students examine solid and fluid materials, demonstrating that solids undergo elastic deformation in response to small forces and fracture in response to large ones, and that fluids tend to maintain a constant volume. They then make a batch of Oobleck -- a viscoelastic material that behaves as a solid in response to short rapid forces and as a liquid in response to slow forces.

Activity dates: 1/19/2023

(BFSU connection: lesson A2)

pdf worksheet

Activity Worksheets: Fall 2022, Forces and Motion

Rotational Inertia

Spinning Tops and Rolling Races

Students gain hands-on intuition for rotational inertia by manipulating spinning toys and by making batons with different mass distributions. They set up races for rolling objects of different shapes (hollow vs solid), relating the rate of rolling to the distribution of mass around the spinning axis. Applications of rotational inertia in sports are discussed.

Activity dates: 10/27/2022

pdf worksheet

Kinetic and Potential Energy

Marble Roller Coasters

Students experience the conversion between kinetic and gravitational potential energy by constructing simple tracks for rolling marbles. Conservation of energy and the loss of mechanical energy due to friction are discussed. Students measure the maximum height of loops and hills that a marble can get over from a given starting height.

Activity dates: 10/20/2022

(BFSU connection: lesson C3)

pdf worksheet

Forces and Flight

Taking Off with Paper Airplanes

Students explore the forces produced by moving air that help an airplane fly. They will experience drag and lift forces directly with paper sheets. They will then make their own paper airplanes and examine how different control flaps affect the behavior of the plane.

Activity dates: 10/13/2022, 5/14/2021

(BFSU connection: lesson C8)

pdf worksheet

Longer version worksheet
Slides from virtual activity

Center of Mass

The Amazing Floating Butterfly

Students will discover how the center of mass serves as the "balance point" of an object. They will find the center of mass of a cut-out butterfly and learn how to shift that center so that the butterfly can be balanced on its extreme tip. They will also explore how placing the center of mass underneath the support allows an object to be in stable equilibrium.

Activity dates: 10/6/2022, 2/12/2021

(BFSU connection: lesson C9)

pdf worksheet
More advanced version: pdf worksheet

Gravity and Projectiles

Time and Range for Projectile Motion.

Students explore what factors affect how long it takes an object to fall and how far it flies while falling. A sound recording app is used to precisely measure times of flight. We learn that gravity makes heavier and lighter objects fall vertically at the same rate, regardless of how far they move horizontally.

Activity dates: 9/29/2022, 5/7/2020

pdf worksheet

Mass and Weight

Measuring the force of gravity

Students will make their own spring scale to measure forces. Using pennies as a standard mass, they will demonstrate that the force with which gravity pulls on an object goes up with the mass of the object. The distinction between mass (amount of material) and weight (force of gravity) will be discussed.

Activity dates: 9/22/2022

(BFSU connection: lesson C3A)

pdf worksheet

Newton's Laws

Exploring forces and inertia with balloon rockets.

Students create balloon rockets that zip across the room. We discuss how jet propulsion works, and explore the effect of mass on how quickly the balloons move. A pendulum is used to see the effect of inertia as the balloon rockets speed up and slow down.

Activity dates: 6/4/2020, 9/15/2022

(BFSU connection: lesson C5, C7)

pdf worksheet


Exploring motion

Students will become familiar with Newton's 1st Law, demonstrating that objects sit still or keep moving with a constant velocity until something pushes them. We will see inertia in action by watching rolling marbles and dropping objects while on the move.

Activity dates: 9/8/2022

(BFSU connection: lesson C5)

pdf worksheet

Activity Worksheets: Past Sessions

Diffusion and Random Walks

Simulating Intracellular Transport

Students will use simulations and model systems to explore how particles move through fluids in the intracellular world. First, we will simulate diffusion by mapping out random walks with dice, demonstrating how inefficient diffusion can be for transport over long distances. The students will then explore actively driven random walks by finding encounter times between hexbug nanobots in different conditions mimicking the crowded and geometrically complex environment inside living cells.

Activity dates: 6/4/2022

pdf worksheet

Diffraction Spectra

Patterns and Rainbows by Diffraction of Light

Students will observe diffraction spectra from light bending around a hair, and use the spectrum to compair hair thickness. Diffraction glasses are used to explore diffraction patterns and notice how different color laser beams make slightly different patterns. The glasses are then used to look at several sources of white light, noting the varying spectrum of colors in each.

Activity dates: 3/26/2022, 2/27/2020

pdf worksheet
Required equipment:

Light Beams and Lenses

Reflection and Refraction of Light

Students explore reflection and refraction by visualizing laser pointer beams bouncing off surfaces and bending at interfaces. We will cut out our own lenses from jello to see light beams converge and diverge, and discuss the optical properties of human eyes. Students also use jello strips as "fiberoptic cables" to bounce laser beams around a corner.

Activity dates: 3/5/2022

pdf worksheet

Activity dates: 11/19/2019, 12/17/2019

pdf worksheet (refraction only)
Required equipment:

Standing Waves and Sound

Visualizing string vibrations and sound

Students will investigate traveling waves by sending pulses through a stretched slinky, and try making standing wave patterns by shaking the slinky with the right harmonic frequencies. They will have a chance to "see" sound by singing into a resonating cavity and watching how the resulting air vibrations make sugar grains dance. Finally, we'll make a variety of toy musical 'instruments', including rubber-band guitars, singing balloons, and a laser-gun-noise maker to demonstrate how resonance chambers amplify sounds. Note: materials listed are for an earlier online version of this activity.

Activity dates: 1/29/2022, 12/9/2020, 12/7/2018

(BFSU connection: lesson C2)

pdf worksheet
Required equipment:


Color-changing Acids and Bases

Students will measure the pH of different house-hold substances using a home-made red cabbage indicator. THey will then carry out a titration to compare two acids with similar pH. Predictions of relative acidity will be tested by measuring the total gas produced in an acid-base reaction and collected with a balloon.

Activity dates: 4/16/2021

Note: This activity is being run virtually in 2021. You will need to provide your own supplies.

pdf worksheet
Required equipment:

Reflection and Refraction

Making Images with Light Beams

Students will visualize light beams by shining laser pointers through juice. Light beams will reflect of straight and curved surfaces, demonstrating convergence and divergence. Refraction will be explored by tracking the path of the beam at the air / juice interface, and observing the effect of a converging lens. Students will also get a first-hand look at images formed by curved mirrors and lenses.

Activity dates: 3/12/2021

Note: This activity is being run virtually in 2021. You will need to provide your own supplies.

pdf worksheet
Required equipment:

Camouflage and Natural Selection

Evolution of the Skittlefish

Students will simulate how visual predation on an animal species can provide evolutionary pressure that leads to adaptations such as camouflage and mimicry. Skittles of different colors will be used to explore natural selection, demonstrating how traits in a population can change over time without any individual animal changing its characteristics.

Activity dates: 1/6/2021

(BFSU connection: lesson B5A)

Note: This activity is being run virtually in 2021. You will need to provide your own supplies.

pdf worksheet
Required equipment:


What determines whether an object floats or sinks?

Students will test common hypotheses for what properties determine whether different objects float (is it size? weight?) and learn about concepts of density and buoyancy. In Part 1, we explore why Legos float while playdoh sinks. In Part 2, we compare the density of eggs, water, and oil.

Activity dates: 10/15/2020

(BFSU connection: lesson A15)

Note: This activity is being run virtually. You will need to provide your own supplies.

pdf worksheet
Required equipment:

Solar System

Modeling Planets

Students put together scale models of the solar system, to explorethe distances between the planets and their relative size. We discuss why scale models are useful and what sort of information they can convey. Students will develop an intuitive sense of size for the planets and the vastness of interstellar distances.

Activity dates: 5/21/2020

Note: This activity is being run virtually. You will need to provide your own supplies.

pdf worksheet
Required equipment:


Investigating properties of fluids.

Students will see how to change whether an object sinks or floats (density), what sets the speed of squirting water (pressure), and the changes in pressure that arise with fast air flow (Bernoulli effect).

Activity by: Michelle Chen

Activity dates: 4/16/2020

Note: This activity is being run virtually. You will need to provide your own supplies.

pdf worksheet
Required equipment:


Modeling virus spread

Students make a model of a virus and its lytic lifecycle, as well as simulating the spread of infectious diseases.

Activity by: Natalie Nady

Activity dates: 4/2/2020

Note: This activity is being run virtually. You will need to provide your own supplies.

pdf worksheet
Required equipment:


What sets the regular ticking of a pendulum?

Students make pendulums and explore which variables affect their swinging frequency. They also observe resonance in action with coupled pendulums.

Activity dates: 3/26/2020

Note: This activity is being run virtually. You will need to provide your own supplies.

pdf worksheet     docx worksheet
Required equipment:

Polymers of Life: Protein and DNA

Exploring material and chemical properties of proteins from an egg and DNA from strawberries

Students learn about the physical properties of polymer solutions (viscoelastic fluids). We examine the consistency of egg whites (a dense protein solution) and how it changes when proteins are cut up by pineapple juice or unfolded by alcohol. Students then extract DNA from a strawberry using alcohol precipitation and examine its similar "slime-like" consistency.

Activity dates: 2/27/2020

Acids and Bases

Blowing up balloons with chemical reactions

Students use pH strips to measure the pH of solutions with different concentrations of citric acid. They add the solutions to baking soda, generating carbon dioxide gas which is collected in a balloon. The extent to which the balloon inflates depends on the initial pH of the solution. Measuring pH afterwards shows whether or not all the baking soda was used up during the reaction.

Activity dates: 11/19/2019, 12/17/2019

Several of the above activities were modified from those developed as part of the LabSci project at Stanford University.
Several are loosely based on suggestions from the Building Foundations of Scientific Understanding curriculum (Vol 1 and 2) by Bernard J. Nebel.