Building Computer Race

Practice is over. The teams are set. All have the same hardware to assemble, the motherboard, processor, RAM, Graphics card and USB Board, but who can assemble the parts, install the Operating system and hook up to the network the fastest.

Making Butanoic Acid

 Making Butanoic Acid from Butanol by refluxing with acidified Potassium Dichromate and then distilling the Acid into a conical flask for later experimentation. Getting students to learn skills by building the apparatus from scratch and discovering all about ground glass joint laboratory equipment.

Circuit emulation

 Setting up circuits in @pascoscientific Capstone, to emulate different electric circuits. Faster than building the circuits for electricity revision, the emulators can calculate the resistances, current and voltages.

Looks like Maths

Many of us have a compartmentalised brain—Chemistry is Chemistry, and Maths is Maths. When students find an easy Maths problem in Chemistry, it is suddenly more difficult because they perceive it as the wrong subject.

Measuring the Speed of Sound

 Measuring the speed of Sound using a tuning fork and a tube, pulling out the slider until the loudest sound can be heard and measuring the distance from the tuning fork. This gives the wavelength. Repeat this several times to get a good average, and then work out how much of a wavelength the distance is calculated at the velocity of sound in air at this temperature.

Site of Respiration

 The Mitochondrion is the site of respiration. Is this an ancient bacterium that invaded another in an example of symbiosis that created a new type of organism? DNA Evidence? Mitochondria self-replicate.

Calculating Depreciation

 ​In Business, depreciation refers to the gradual decrease in value of an asset over time due to factors like wear and tear or obsolescence, and it's a key accounting concept used to allocate the cost of an asset over its useful life. 

How a hard disk works

 Taking a hard disk to bits so that the students could see how a hard disk works.

Displacement reactions

Using displacement reactions, comparing the reactivities of three different metals with their sulfates—Copper, Iron, and Zinc—to find out which is the most reactive and which is the least.

Gay Lussac's Law

 Constant volume: Increasing the Temperature increases the pressure—Gay Lussac's Law. It is so much easier and more accurate to use a @pascoscientific wireless pressure sensor than a Bordon Gauge.

Cards and Probability

Many questions in Maths Papers look at the probability of selecting a card but many students don't play cards except perhaps on a computer games and don't know the names, values or suits.

 

The Laplace rail demonstration

The Laplace rail demonstration is a piece of scientific equipment used to demonstrate the force exerted on a current-carrying conductor in a magnetic field, illustrating the motor effect and fundamental electromagnetic principles. 

Spirogyra

 Life is beginning in the pond and it is a good time to look at spirogyra and get the students to try and record what they actually see rather than what they think they see.

Food Rewards

 A-Level Psychology: We are what we eat. Does what our mother ate when pregnant affect what we like to eat and does letting kids have food rewards help them in the long term?

Analog Computers

 A Level Computing. Looking at different types of computers, including some analog computers.  Unlike digital computers that use discrete data, they use continuously variable physical quantities, like voltage or mechanical motion, to model and solve problems.

What’s So Special About the Dative Covalent Bond?

A-Level Chemistry: What is the difference between a normal covalent bond and a dative covalent bond. Although the electrons are shown differently in a diagram, there is no difference between them in reality, and in reactions, any of the bonds might be broken.

What’s So Special About the Dative Covalent Bond?

When you first learn about covalent bonding in GCSE Chemistry, it's pretty straightforward: two atoms share a pair of electrons to fill up their outer shells and become more stable. But at A-level, things get juicier. You’re introduced to a slightly more complex version of the covalent bond—the dative covalent bond, also known as a coordinate bond.

So, what is this mysterious bond, and how is it different from the good old ordinary covalent bond? Let’s break it down.

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🧪 The Ordinary Covalent Bond

In a normal covalent bond, each atom provides one electron to the shared pair. Think of it like two friends splitting the bill at a café: one pays for the coffee, the other for the cake. Fair and square.

For example:

• In a molecule of hydrogen (H₂), each hydrogen atom has one electron. They come together and share, forming a bond with a pair of electrons—one from each atom.
• In oxygen gas (O₂), each oxygen shares two electrons, forming a double covalent bond.

This sharing allows both atoms to achieve a stable electron configuration (often the noble gas configuration).

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🎯 Enter the Dative Covalent Bond (Coordinate Bond)

Now imagine a situation where one atom provides both electrons for the bond. This is a dative covalent bond.

It’s like one friend paying for the entire meal while the other friend just turns up and enjoys the food. Generous? Perhaps. But both still get a good time out of it—just like both atoms benefit from the bond.

💬 Key Definition:

A dative covalent bond is a type of covalent bond in which both electrons in the shared pair come from the same atom.

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🌟 Examples of Dative Covalent Bonds

1. Ammonium Ion (NH₄⁺)

• Ammonia (NH₃) has a lone pair of electrons on the nitrogen atom.
• A hydrogen ion (H⁺), which has no electrons, comes along.
• Nitrogen donates both electrons from its lone pair to form a bond with the H⁺.
• The result? An ammonium ion with four N–H bonds—one of which is dative.

✏️ We usually show the dative bond with an arrow pointing from the donor atom:

![N → H⁺]

2. Aluminium Chloride (Al₂Cl₆)

• In its dimer form, one aluminium atom (electron-deficient) accepts a lone pair from a chloride ion.
• This donation creates a dative bond from Cl to Al.

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🧠 So… What’s the Difference Again?

Feature	Ordinary Covalent Bond	Dative Covalent Bond
Electron Contribution	One electron from each atom	Both electrons from one atom
Still Covalent?	✅ Yes	✅ Yes
Representation	Single line (–)	Arrow (→), from donor to acceptor
Example	H₂, O₂, CH₄	NH₄⁺, Al₂Cl₆, H₃O⁺

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🎓 Why Does It Matter?

At A-level, understanding who's donating what in a bond is essential—especially when it comes to:

• Drawing correct dot-and-cross diagrams
• Naming ions and compounds
• Predicting shapes of molecules (VSEPR theory)
• Understanding acid-base behaviour (in Bronsted-Lowry and Lewis terms)

It also appears in:

• Transition metal complexes
• Biological systems (e.g. haemoglobin binding O₂)

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🧪 Summary

Dative covalent bonds are just a special case of covalent bonding, where one atom does all the sharing. It’s still covalent, it still involves shared electrons, but the ownership history of those electrons tells us a lot about chemical reactivity and structure.

Next time you see a lone pair looking for something to bond with—ask yourself: “Could this be a dative bond moment?”

 

Firmware up to date

 Some of the regular jobs using the @pascoscientific sensors is the keep all the firmware up to date and charge or change the batteries so the sensors are ready for action.

Different sided dice

 Changing the probabilities: Instead of the usual 1/6, we looked at 3—to 9-sided dice to see how the probabilities changed. It was also interesting to see the shapes that these dice made.

Steam Engine

 Energy transfers using a steam engine. There is nothing like having a steam engine in the classroom. The interest level goes up and so does the enthusiasm to control the engine and make hammers work and polishers polish.

Plating results

Investigating the effects of Mint and Garlic on the growth of bacteria. The results were not as good as we had hoped. With different concentrations only the most concentrated had any effect on the development of bacteria, suggesting that these bacterial agents are not that effective.

 

Parliamentary Makeup

 A-Level Sociology. Does Parliament reflect the social makeup of the population it represents in 2025? Book stats are out of date. There is a 60:40 split in men to women. Nearly 24% of MPs went to independent schools and 85% are University graduates. How do you feel about the social makeup?

BSOD

 What is the Blue Screen of Death? What does it mean, and how can we recover from it? A-level computing students find out how to fix the machine so it works again.

Rusting

 Three test tubes after a few weeks. The staple in water and air had all but rusted away, the one in air but no water was untouched, and the one with water and no air because of the oil had only a joint of rusting. The students had to explain why.

Elastic Collisions

Using the magnets on two smartcarts to demonstrate elastic collisions. Using the @pascoscientific Capstone, the before and after graphs can quickly be compared to show the change in momentum and that it is conserved.

 

Practical Maths

 Practical Math. It is okay to do some Math problems, but sometimes it is nice to see and understand the Physics behind them. What is an elastic collision? Watching the Newtons cradle gave an idea about what the Mechanics problem was all about.

Goldleaf Electroscope

 The Goldleaf electroscope is such a simple piece of equipment yet one of the most useful. I have tried this with dutch metal but only with gold leaf does it work exceptionally well. With a decent UV light is demonstrates the photoelectric effect well.

Investigating mint and garlic

 Microbiology at A Level: Investigating the effect of Mint and garlic extracts on bacteria cultures. Which one is the most effective and why? Are there any other plant extracts that work like this? So, in addition, we are investigating some other herbs to see if they kill bacteria too.

Hardness of the Alkali Metals

Investigating the reactivity and properties of the Alkali Metals. Cutting each of the metals in turn with a sharp scalpel. Lithium was the hardest and stayed shiny the longest, and Potassium was the easiest to cut and tarnished as it was cut.

 

Magnetic Fields

 Using the @pascoscientific magnetic field probe along with the smartcart or a rotation sensor to get a reading of the magnetic field strength as the probe moves further into different magnetic fields

Globaslisation

 A level Business Studies—Globalisation The Earth is becoming smaller, and it is often cheaper to move manufacturing items around the world to be constructed than to do them in the same country. Maybe Trump will change the way the world works.

Youngs doble slit experiment

​Exploring wave-particle duality with my A-level Physics students. Doing experiments demonstrating light behaving like a wave and also acting as particles – it’s hurts the brain how the universe plays by both rules!

 

Infection Games

 Playing an infection game to simulate the growth of an infection in a population, and then repeating the game using vaccination to see the effect this has on the rate of an infection. 

Flowcharts

 ​Teaching flowcharting is key to writing better computer programs!  It helps the students visualize logic, simplifies problem-solving, and boosts code clarity. Perfect for beginners to understand the flow and structure before diving into code.

Using a calorimeter.

 I find that many students have not used a colorimeter or even what one looks like. Their idea of an entropy experiment is to heat a beaker of water, not considering heat loss. Comparing two experiments, we had a difference of hundreds of Joules.

Circle to a sine wave

 Using a Lego model to convert a circular motion into a sine wave to demonstrate the relationship between the trig functions and the circle.

Bartons Pendulums

 Setting up Barton's Pendulums to demonstrate resonance on a string is a breeze with this kit from @lascells. It's fascinating to see how the driving frequency of one ball influences the others. The ball of the same length starts to swing, absorbs the energy, and causes the first to stop—then the cycle repeats!

Understanding Resonance Through Barton's Pendulum

Resonance is a powerful and captivating phenomenon in physics that explains how oscillating systems can transfer energy between each other. It occurs when a system is driven at its natural frequency, leading to a dramatic amplification of the oscillations. One of the most striking demonstrations of resonance is the Barton's Pendulum. This simple yet effective setup offers a hands-on way to visualize the concept of resonance in motion.

What is Resonance?

Before diving into Barton's Pendulum, let's first understand resonance. Every object or system has a natural frequency at which it tends to vibrate. When an external force or energy is applied at this natural frequency, the object begins to oscillate with increasing amplitude, resulting in resonance.

This is like pushing a swing at just the right moment. If you push at the swing's natural frequency (the timing when it moves the most), you can make it swing higher and higher. The energy from your pushes accumulates in the system, amplifying the motion.

Resonance can be found in many physical systems, from musical instruments like guitars and violins to the human body and even in buildings during earthquakes. It plays a key role in both engineering and natural phenomena, both helping and hindering the design of structures and devices.

What is Barton's Pendulum?

Barton's Pendulum is a classic physics demonstration that vividly shows how resonance works in a mechanical system. It consists of a string with a series of pendulums (small swinging balls) attached to it, with one pendulum being used as the driving force and the others as passive receivers.

In this setup, one ball is set into motion with a push, and its oscillations start to drive the motion of other balls that are attached to the same string. The key point here is that the balls on the string have different lengths (and hence, different natural frequencies). When the driving ball oscillates at a frequency that matches the natural frequency of one of the other balls, it transfers energy to that ball. This ball begins to swing in sync with the driving ball, causing the first ball to stop. The energy transfer continues as the pendulums oscillate back and forth in a repeating cycle.

How Does Barton's Pendulum Demonstrate Resonance?

The beauty of Barton's Pendulum lies in its ability to visually show the transfer of energy between oscillating bodies. Here's how it works step-by-step:

1. The Driving Ball: One ball (often the first one) is given an initial push to start it oscillating.

2. Energy Transfer: As this ball swings back and forth, it imparts energy to the other balls. The key is that this energy transfer only occurs effectively when the driving ball matches the natural frequency of another ball.

3. Synchronization: When the balls on the string are of the same length (or close to it), they share the same natural frequency. When the driving ball hits the right frequency, it will begin to synchronize with another ball, causing that ball to swing and absorb energy from the first one.

4. Oscillation Cycle: The cycle repeats. As one ball receives energy, the other stops moving and the process begins again. This continuous transfer of energy is a direct demonstration of the resonance phenomenon.

Why Does This Happen?

This energy transfer occurs because of the natural frequency of each pendulum. When a ball is driven at its resonant frequency, the amplitude of its oscillation increases. Since the pendulums are connected by the string, they share this energy, and it causes the other pendulums to swing in response.

The exact mechanics of the transfer are dictated by the physics of waveforms and resonance. When the frequency of the driving ball matches the natural frequency of a passive pendulum, energy flows efficiently between them, amplifying the oscillations.

Why Is Barton's Pendulum Important?

The Barton's Pendulum is an excellent teaching tool for understanding the principle of resonance. It offers a clear and visually engaging way to explain an often abstract concept. Additionally, it highlights the importance of resonant frequencies in mechanical systems, which has real-world applications in fields such as engineering, architecture, and even medicine.

Applications of Resonance

Understanding resonance and its applications is crucial for engineers and designers. In construction, for example, resonance is taken into account when designing buildings, bridges, and other structures to ensure they can withstand vibrations caused by factors like wind, traffic, or even earthquakes.

In technology, resonance is used in musical instruments, electrical circuits, and tuning systems to enhance performance and efficiency. It also plays a vital role in medical devices, such as MRI machines, where specific resonant frequencies are used to produce clear images of the body.

Conclusion

Barton's Pendulum is an intriguing demonstration that brings the abstract concept of resonance to life. By showing how energy is transferred between oscillating bodies, it makes it easy to visualize how resonance can amplify motion. From its fundamental principles to its real-world applications, resonance is a fascinating phenomenon that continues to influence many fields, from engineering to medicine. Whether you're a student or a science enthusiast, the Barton's Pendulum setup is a perfect tool to explore the power of resonance in action.

Hornwort

 Trying to find a good aquatic plant for photosynthesis experiments in the laboratory. Hornwort (Ceratophyllum dermersum) does about the best. Being a native species, it grows well in my pond all year round, so it also has good availability.

Evidence for brain damage

​Should schoolchildren head the ball? In our ​ A Level Psychology class we dug into whether lighter balls are truly safer and if heading could lead to brain damage. Research reveals some surprising insights!

Benzene

 Looking at a structural model of the benzene bonds to see if we can understand why it reacts the way it does and how we arrived through history to this model.

Momentum

 Investigating Momentum with elastic and inelastic collisions using the @pascoscientific smartcarts. Using either the velcro or the magnets, simple collisions can be measured, and using multiple stacked carts, we can simulate changing the mass visually.

Two Protractors

 Two protractors, the one on the left makes it easy for the students to do bearings, and the one on the right is the one that students have in their pencil case, which makes doing bearings much more difficult.

Total Internal reflection

 Seeing what we can do with total internal reflection - communicating down fibres, lighting Christmas trees and using endoscopes.

Knitted Gut

 c

Poverty is complex

A-level Sociology Poverty is complex—no single measure tells the full story. Stats are just snapshots in time. The amount of income is only a vague yardstick. By using different measures & perspectives, we get a clearer picture. #Sociology