Which of the following represent a systematic error when measuring the mass of an anhydrous object? Anhydrous means that the object has been completely dried out. All the water has been left out of the object or evaporated out of the object. Now, when it comes to a systematic error, it's predictable in the sense that it's always going to give us a value that's too high or too low from the agreed upon value. But in its predictability, there is some problem involved. Because of this predictability, we can't easily detect it.

The only way I would know if something is giving me a number that's too high or too low is that if I have the agreed upon value ahead of time, which is called your theoretical value. OK, without that value, you won't know for sure if a systematic error is occurring. A good thing about systematic error is if you know that you have it, all you have to do is correct the design of your experiment. By correcting it, you can eliminate that error.

Knowing this now, let's take a look at the options. Here. We say you weigh the object before all the water has evaporated. So you're weighing an object. It's supposed to be completely dry, but you haven't given enough time to dry out, so you're going to get a mass that's too high. This is a flaw within the experiment. You didn't wait long enough for you to drive out all of the water, so this is definitely a systematic error. All you got to do to correct it is wait more time. Always wait as long as possible in terms of drying. Get all the water out and then you'll get the right mass of the dry object.

The scale used has not been properly calibrated, so this is a big thing. Anytime you start a lab you they always tell you to calibrate your pipettes, calibrate your beer rats, calibrate on your scales. This ensures that the number that you're going to get is as close to the agreed upon value as possible. So again, that's another flaw within the system. All you got to do to get rid of that error is calibrate the scale.

Next, air flow near the balance causes the precise mass to vary All right, so air flow. It's hard to control the flowing of air as you're opening up the scale and putting your your object and then closing the door behind it. So air flow is something that's outside your realm of control. Because of this, it's a random error. That air flow won't always be present, so it won't always affect the mass that you have.

You write down the incorrect mass of the anhydrous object, so here you didn't write down the correct number. This is a little bit tricky. Could this be systematic error? Or could this just be a random error on your part because you're not always going to write down the wrong number? We're going to say here that this could fall under a systematic error because within the design of your experiment, you're supposed to always double check, triple check all your numbers and values to make sure they make sense. The fact that she wrote down the wrong number and didn't go back and check it is a flaw in design of your experiment. You tell yourself, if I write down a number, I have to look at it multiple times to make sure it's the correct number that I'm writing.

So we could say that the fourth option would fall under systematic error as well. So here we'd say that 1-2 and four are your systematic errors, although 4 you could be open to saying that it's a random error as well because you're not always going to make that mistake. So guys, remember the difference between systematic error and random error and how they together give us a good impression of what experimental error could be.