Laboratory Scales II

Dr. Smith smiles warmly as she addresses you and Emma. “Let’s practice what we learned! Year 2 has a plant growth experiment scheduled, and they need 3.5 grams of fertilizer per setup. Your task is to weigh the fertilizer using the analytical balance and place it in the labeled plastic bags.”

Emma eagerly places the plastic bag on the balance and adds fertilizer, announcing, “We’ve got 3.5 grams!” She hands the result to you for recording.

You check the measurement. ‘Hmm, that reading is 3.55g but it’s close enough. Right Dr Smith’. 

Dr Smith: ‘Actually, the point of using an analytical balance is to make sure that the reading is precise. Let’s see if we can figure out where the error crept in.” 

Dr Smith closes her notebook, looking at both of you. “Think carefully about each possibility. Which do you believe is the most likely reason for the odd measurement?”