Lamps: let’s be clear!

Distant teaching activity

Teachers: Mario Di Fonza in collaboration with Sabrina Nappi, Riccardo Di Pietro, Rosanna Busiello

Age: 14-16 years old. February-march

Let’s start with some questions! 

Which kind of lamps can we buy after the old incandescent bulb, invented by Edison, has retired? Which are the energy-efficient light bulbs and which ones emit less CO2 in the environment? Which parameter helps us understand how much light a light bulb really emits? How much money can we save using led lamps compared to incandescent lamps? How long can we keep the incandescent lamp on? How long does it take to pay back a led purchase? Students will learn different types of light bulbs on the market in order to know the consequent energy and money savings.

This activity could be introduced on April 22nd, “Earth Day”, a celebration of the environment and the protection of the Earth.

If you check the website you can read the descriptions of every activity.

We chose Inquiry Based Science Education (IBSE) methodology in which research is the most important task of pedagogical approach because it encourages students to ask questions and develop actions to solve problems and understand phenomena.

Subjects involved are maths,chemistry and physics


Students are asked to take a look around and observe the amount of unnatural light used to illuminate the rooms of their flat and make a list of the types of light bulbs placed in every room, the lighting systems (chandelier, spotlight, etc.), their placements and everything they think can contribute to the brightness of the rooms. 

Here are some answers:

Secondly, students are asked to make an outline of the plan of the house pointing out the number of light bulbs.


The teacher asks the students the following questions: Have you ever wondered how can be possible to obtain light from an electric current?  Which are the systems allowing this conversion? 

Lumen and Watt are two essential units of measurement in choosing the lamp which best suits our needs. Even though it’s easy to confuse them, we’d better avoid the mistake to choose a lamp only considering the wattage. Students are invited to watch the video about Lumen and Watt and then they have to find out some precious tips to save time and money. After watching the video, students write the words and terms about the analysed phenomena distinguishing the ones they already knew from the new ones.

Students explore the circuit with the lamp in the app changing the values of electrical quantities and make the measurements with the instruments supplied. 

They fill out the laboratory report after making observations and measurements. This phase of the activity is a good moment to make a connection with chemistry.

There are many ways to produce energy. The energy sources we use in daily life are made up of chemical elements reacting in different ways. The main one is definitely carbon (C), identified as the main cause of climate changes because we can find it in climate-altering gas

Carbon, if burnt, is able to bind with oxygen particles in the air generating CO2, that is carbon dioxide. Students have to check the periodic table to find the carbon; secondly, they take note of the number of chemical bonds carbon can create, keeping in mind that the electronic configuration imposes the orbital filling  Check the periodic table and find the carbon.


By mentioning The ONU Agenda 2030 for the sustainable development, CLEAN AND ACCESSIBLE ENERGY students have to watch the video :

Ensure access for everybody to low-cost, reliable, sustainable and modern energy systems. In the world, the share of energy coming from renewable sources has reached the 17.5% of final consumption. In Italy, the leaders of clean energy consumption are Valle D’Aosta (89%) and the autonomous provinces of Trento (45%) and Bolzano (66%), while the national average still stands at 17%.

With the growth rate of renewable energies in the last five years, Italy will not reach the UN Target by 2030.

We verified that when you buy a new light bulb it’s important to refer to the lumen (lm), not to watts. Lumen, in fact, is the parameter to understand how much light a light bulb really supplies. A 600 lm light bulb is equivalent to a 12 watt led lamp with low energy consumption and to a 60 watt incandescent lamp.

Students complete the following chart pointing out at least one example for each type of lamp (neon, filament, fluorescent, led, etc.) searching information on the internet, or asking in a hardware store.

Another connection with chemistry:

It’s essential to choose a lighting system producing a little amount of CO2, but we can also act upstream during the electrical energy production phase. Students are asked to answer this question: what do the clean energy production systems have in common? The decarbonisation. Decarbonisation is the process of reducing the carbon-hydrogen ratio in energy sources.

Students have to calculate the carbon-hydrogen ratio in the following compounds:

• Wood, composed of cellulose
• Carbon C
• Petroleum, a mixture of compounds containing carbon and hydrogen atoms whose percentage is ….

After the analysis the question is: what do you notice?


Eventually, students are encouraged to watch this video.

After learning concepts about lighting and how to reduce global warming risks, they can try to plan again the lighting system in their flat: how many lumens do I need for my room?

This is a possible answer:

Students are asked to plan again their house lighting system for their cleanest.