Pre-SGO

An atom is electrically neutral because

• Neutrons balance the protons and electrons.

• The numbers of protons and electrons are equal.

• The numbers of protons and neutrons are equal.

• Nuclear charges stabilize the charges.

Using a metric ruler, you find the sides of a rectangular piece of plywood are 3.54 cm and 4.85cm. To the correct number of significant figures, the area of this plywood should be expressed as

• 17.2 cm²

• 17.169 cm²

• 17.1 cm²

• 17.17 cm²

Chlorine has the atomic number 17 and mass number 35. It has

• 17 protons, 17 electrons and 18 neutrons

• 35 protons, 35 electrons, and 17 neutrons.

• 17 protons, 17 electrons, and 52 neutrons.

• 18 protons, 18 electrons, and 17 neutrons.

Use the chart below to answer question #4

Student A: Trial 1: 1.43 g, Trial 2: 1.52g, Trial 3: 1.47g, Trial 4: 142g

Student B: Trial 1: 1.43g, Trial 2: 1.40g, Trial 3: 1.46g, Trial 4: 1.44g

Student C: Trial 1: 1.54g, Trial 2: 1.56g, Trial 3: 1.58g, Trial 4: 1.50g

Student D: Trial 1: 0.86g, Trial 2: 1.24g, Trial 3: 1.52g, Trial 4: 1.42g

• Student A

• Student B

• Student C

• Student D

The table shows the procedure for two experiments.

Experiment 1: Procedure: Max Iron filings and sulfur powder in a china dish and run a magnet through the mixture.

Results: The iron filings got attracted to the magnet. The sulfur powder remained in the china dish.

Experiment 2: Procedure: Baking soda was added to vinegar in a test tube.

Results: A gas fizzied out of the test tube. No odor was given off.

Which of the following conclusions can be made based on the results of the experiments.

• Physical change occurred in both experiments.

• A chemical change occurred in experiment and a physical change in experiment 2

• Chemical change occurred in both experiments.

• A physical change occurred in experiment 1 and chemical change in experiment 2

420 ml 0f water is equivalent to

• 0.420 cm³

• 420L

• 420000L

• 420 cm³

The number of grams equal to 0.5 kg is

• 0.0005

• 500

• 0.005

• 5000

To two significant figures, the measurement 0.0255 g should be reported as

• 0.02 g

• 0.025 g

• 0.026 g

• 2.5 x 10² g

The measurement that has only non-significant zero is

• 0.0037 ml

• 60.0 ml

• 506 ml

• 400ml

Written in scientific notation, the measurement 0.000065 cm is

• 65x10^-4cm

• 6.5x10^-6 cm

• 6.5x10^-5 cm

• 6.5x10^-4 cm