Salt Circuit Experiment

Discover how electricity travels through various materials with this simple salt circuit experiment! Paint with salt and glue to light up an LED while learning about conductors, insulators, and simple circuits. This fun STEM activity combines art, science, and a touch of engineering (STEAM). It’s perfect for classrooms, STEM centers, or at-home learning.

Field: Physics — Electricity
Grades: 2–5
Concepts Explored: Electric circuits, conductors, insulators, electrons, and energy transfer.

Electricity needs a complete path, or circuit, to flow. In this project, saltwater acts as a conductor because the ions in the salt allow electricity to move from one end to the other. The battery provides energy that travels through the salty glue line, lighting up the LED. The glue and salt create a fun, visible “wire” that shows how electric current can move through different materials.

🔎 Find all of our Electricity Experiments for Kids here.

Materials Needed for the Salt Circuit Project

Watercolor paper or cardstock
White glue
Table salt
Watercolors and paintbrush
Scissors
LED light
9V battery

How to Make a Salt Circuit

STEP 1: Gather all your materials.
STEP 2: Cut the paper in half to make two smaller sheets.
STEP 3: Draw a squiggly line with glue from the bottom to the top of the paper, ending at the edge. Make sure both pieces of paper have glue lines that touch the edges facing each other.
STEP 4: Sprinkle salt generously over the glue and shake off the excess.
STEP 5: Use watercolors to gently paint over the salty glue.

draw a squiggly line of glue, sprinkle with salt, and color with watercolors

STEP 6: Once slightly dry, insert the LED light into the salt line near the top

add an LED light to both ends of the path

STEP 7: Touch the 9V battery to the salt line at the bottom.

touch the battery to both ends of the salt glue path

STEP 8: Watch as the LED lights up through the salty glue path!

Complete salt circuit with battery and light up LED

Science Concepts Behind the Salt Circuit

🔎 If you’d like to learn more about the science behind salt painting, read more here.

Electricity is the flow of tiny charged particles called electrons. For these electrons to move, they need a path that conducts electricity — a conductor. Materials like metal, water, and salt solutions conduct electricity well because their particles allow electrons to move freely.

In this experiment, the battery acts as the energy source. The salt and water in the glue make a conductive path. When the circuit is complete — from the battery, through the salt path, to the LED — electricity flows, and the LED lights up.

If the circuit is broken, dry, or missing a connection, the LED won’t light, indicating that electricity must travel in a closed loop to function properly.

💡 Tip: Try comparing your salt circuit to one made with plain dry glue or dry salt to see how conductivity changes!

NGSS Guiding Questions:

What materials conduct electricity best?
➤ Metals and saltwater are great conductors because their particles allow electricity to flow easily, while materials like plastic, paper, and rubber are insulators that block electricity.

What happens when electricity flows through a complete circuit?
➤ The electricity can move from the battery to the LED light and back again, creating a closed loop that makes the light turn on.

How does salt help electricity travel through the glue line?
➤ Salt contains ions that carry an electrical charge. When mixed with water, these ions help electricity move through the glue path.

Salt Circuit Facts for Kids

Saltwater is a conductor, but pure water isn’t!
LEDs (Light Emitting Diodes) use less energy than regular light bulbs.
Insulators, such as rubber or plastic, prevent electricity from flowing.
Conductors allow electricity to move easily, like metals, saltwater, and certain liquids.

Extension Ideas & Variations for the Salt Circuit Experiment

Try creating different glue paths — straight, zigzag, or spiral — and observe the resulting changes.
Experiment with other materials, such as sugar, baking soda, or sand, to see if they conduct electricity.
Create art circuits — add paint, shapes, and design your own glowing artwork!