Questions: A chemist needs to know the mass of a sample of MgCl2 to 2 significant digits. He puts the sample on a digital scale. This is what the scale shows: 0 2 0 8 3 7 g If this measurement is precise enough for the chemist, round it to 2 significant digits. Otherwise, press the "No solution" button. g 10 No solution

A chemist needs to know the mass of a sample of MgCl2 to 2 significant digits. He puts the sample on a digital scale. This is what the scale shows:
0
2
0
8
3
7 g

If this measurement is precise enough for the chemist, round it to 2 significant digits.
Otherwise, press the "No solution" button.
g
10
No solution

Transcript text: A chemist needs to know the mass of a sample of $\mathrm{MgCl}_{2}$ to 2 significant digits. He puts the sample on a digital scale. This is what the scale shows: 0 2 0 8 3 7 g If this measurement is precise enough for the chemist, round it to 2 significant digits. Otherwise, press the "No solution" button. $\square$ g $\square$ 10 No solution

Solution

Solution Steps

Step 1: Understand the Problem

The chemist needs the mass of a sample of $\mathrm{MgCl}_{2}$ rounded to 2 significant digits. The digital scale shows the mass as 0.20837 g.

Step 2: Identify Significant Digits

Significant digits are the non-zero digits and any zeros between them or after a decimal point. In the number 0.20837, the significant digits are 2, 0, 8, 3, and 7.

Step 3: Round to 2 Significant Digits

To round 0.20837 to 2 significant digits:

Identify the first two significant digits: 2 and 0.
Look at the third significant digit (8) to decide whether to round up or down. Since 8 is greater than 5, we round up.

Thus, 0.20837 rounded to 2 significant digits is 0.21.