# Exams with ChatGPT

Last year, there was a question in my exam, it was about measuring the density of 100 g of solder particles, to be used in a solder paste, and determine the alloy based on the density. The equipment is only a balance and vernier calliper, which cannot precisely determine the size of a small particle. Then we had to propose another method, using a readily available equipment in a home or a typical laboratory.

This question had me stumped for a while, until I had a eureka moment when I went for a bathroom break. Mind you, this was an all aids permitted exam. Maybe if you’re not under pressure, it’s easy to find that Archimedes principle can be used. But this scenario wouldn’t have been easy to Google unless you know what you’re looking for.

ChatGPT has taken the world by a storm. Sometimes, when you give them a prompt, it sounds like the AI really knows what it’s talking about. I was curious to see if it can come up with an answer, and it did.

Prompt #1: You have 100 g of solder particles, intended to be used for solder paste. The alloy of the particles is unknown, but it is the same for all particles. The particles appear to be spherical, with some distribution in size. You shall measure the mass density of the particles, to have an indication of what alloy is used. The equipment you have is a balance and vernier calipers, propose a method for precise measurement of mass density

ChatGPT: Here is a proposed method for measuring the mass density of the 100g of solder particles:

1. Measure the diameter of a representative sample of particles using vernier calipers. Take at least 10 measurements to get an average diameter and standard deviation.
2. Use the average diameter to calculate the volume of each particle, assuming they are spherical.
3. Weigh a sample of the particles, and use the weight and volume to calculate the mass density of the sample.
4. Repeat steps 2 and 3 several times to get multiple samples, to get a more accurate average mass density.
5. Finally, calculate the average mass density of all the samples, and use the standard deviation to determine the precision of the measurement.

Prompt #2: Do you have other recommendation for an even more precise method?

ChatGPT: Yes, here is another method that could give you even more precise results:

1. Use a more precise balance, such as an analytical balance, to measure the weight of the samples.
2. Instead of using vernier calipers, consider using a scanning electron microscope (SEM) to get an even more accurate measurement of the particle size and shape.
3. In addition to measuring the mass density, you could also use energy-dispersive X-ray spectroscopy (EDS) in combination with the SEM to determine the composition of the particles, which can be useful in identifying the specific alloy being used.
4. To further improve precision, consider increasing the sample size and measuring multiple samples to get a more representative average value.

Prompt #3: What if I don’t have a SEM and still want a more precise measurement?

ChatGPT: If you don’t have access to a Scanning Electron Microscope (SEM), here are some additional steps you can take to improve the precision of the mass density measurement:

1. Use a more precise balance, such as an analytical balance, to measure the weight of the samples.
2. Consider using image analysis software to more accurately measure the particle size and shape from optical microscopy images.
3. In addition to measuring the mass density, you could use X-ray diffraction (XRD) or X-ray fluorescence (XRF) analysis to determine the composition of the particles, which can be useful in identifying the specific alloy being used.
4. Consider using more advanced statistical methods to analyze the data, such as Monte Carlo simulation or bootstrapping, to estimate the precision of the measurement.
5. To further improve precision, consider increasing the sample size and measuring multiple samples to get a more representative average value.

Prompt #4: I still don’t want to use any microscope to measure the density, any other ideas?

ChatGPT: If you don’t want to use a microscope to measure the density of the solder particles, here are some additional steps you can take to improve the precision of your measurement:

1. Use a more precise balance, such as an analytical balance, to measure the weight of the samples.
2. Consider using image analysis software to more accurately measure the particle size and shape from optical microscopy images.
3. In addition to measuring the mass density, you could use X-ray diffraction (XRD) or X-ray fluorescence (XRF) analysis to determine the composition of the particles, which can be useful in identifying the specific alloy being used.
4. To further improve precision, consider increasing the sample size and measuring multiple samples to get a more representative average value.
5. Consider using statistical methods such as bootstrapping or Monte Carlo simulation to estimate the precision of the measurement.

Prompt #5: You still recommend using image analysis software and optical microscope, is there any other way?

ChatGPT: Yes, here is an alternative method that does not involve image analysis software or an optical microscope:

1. Use a more precise balance, such as an analytical balance, to measure the weight of the samples.
2. Measure the volume of the sample by a displacement method. This can be done by adding the particles to a known volume of water or a fluid of known density, and measuring the change in fluid volume.
3. Use the weight and volume measurements to calculate the mass density of the sample.
4. Repeat steps 2 and 3 several times to get multiple samples, to get a more accurate average mass density.
5. Finally, calculate the average mass density of all the samples, and use the standard deviation to determine the precision of the measurement.

Finally, at the fifth prompt, ChatGPT uses a water displacement method. Some of the details of the exam question were omitted in the prompt, but it was amusing nonetheless to see ChatGPT in action. Some of the suggestions were overkill for the task and some were reasonable but not impactful. I could imagine seeing ChatGPT being one way to help brainstorming for ideas. A realistic prediction would be that there are no more all-aids permitted exam in the future!