measuring mass\n4. what is the precision of this electronic balance?\n5. what are two things you should do…

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:

4. 0.1 g
5. Before: Make sure it's on a level surface and zeroed. After: Clean the pan and turn it off.
6. 635.8 g
7. 101.8 g