Question

measuring mass

1. what is the precision of this electronic balance?
2. what are two things you should do before and after you use a balance?
3. mass
4. mass

Explanation:

Step1: Determine precision from scale

The smallest division on the scale of the electronic balance is 0.1 g. So the precision is 0.1 g.

Step2: List pre - use actions

Before using a balance, one should make sure it is on a level surface and that the balance is zeroed (tared).

Step3: List post - use actions

After using a balance, one should clean the balance pan and turn off the balance.

Step4: Calculate mass for question 6

The top scale reads 30 g, the middle scale reads 600 g and the bottom scale reads 5.8 g. So the mass is \(30 + 600+5.8=635.8\) g.

Step5: Calculate mass for question 7

The top scale reads 0 g, the middle scale reads 100 g and the bottom scale reads 1.8 g. So the mass is \(0 + 100+1.8 = 101.8\) g.

Answer:

1. 0.1 g
2. Before: Make sure it's on a level surface and zeroed. After: Clean the pan and turn it off.
3. 635.8 g
4. 101.8 g