unit 1

Question 1

What are the rules for determining the number of significant digits?

Answer 1

All non-zeros are significant.
All sandwich zeros, or zeros between non-zeros, are significant.
Leading zeros or zeros that start a number are not significant.
Trailing zeros or zeros that end a number are only significant if there is a decimal point anywhere in the number.

Question 2

Determine the number of significant digits in the following measurements:
0.00628 mm

Answer 2

3 significant digits

Question 3

Determine the number of significant digits in the following measurements:
3,089 mg

Answer 3

4 significant digits

Question 4

Determine the number of significant digits in the following measurements:
10,100 dg

Answer 4

3 significant digits

Question 5

Determine the number of significant digits in the following measurements:
0.050 kg -

Answer 5

2 significant digits

Question 6

Determine the number of significant digits in the following measurements:
100.0 mL

Answer 6

4 significant digits

Question 7

Write the names of the units from the question above.
mm
mg
dg
kg
mL

Answer 7

millimeters
milligrams
decigrams
kilograms
milliliters

Question 8

What is the difference between physical changes and chemical changes?

Answer 8

Physical changes do not alter what the substance is, only the appearance. Chemical changes do alter what the substance is and can also change the physical look of the substance.

Question 9

Provide three examples of physical changes and three examples of chemical changes.

Answer 9

Physical Changes - cutting, breaking, melting
Chemical Changes - reacting, rusting, exploding

Question 10

What is the definition of matter?

Answer 10

Matter is anything that has mass and takes up space (volume). In the simplest form, matter is atoms.

Question 11

Describe the difference between macroscopic and microscopic observations.

Answer 11

Macroscopic can be seen with your eyes, while microscopic cannot be seen with your eyes. Chairs and tables are macroscopic, while germs and bacteria are microscopic.

Question 12

What is precision? What is accuracy?

Answer 12

Precision is the ability to get the same results over and over again, meaning they are close to each other, but not necessarily close to the correct or true answer.
Accuracy is the ability to get results close to the true or correct answer.

Question 13

What are the three states of matter? Describe the shape and volume of each of the states.

Answer 13

Solids - have a fixed shape and volume
Liquids - have a fixed volume, but take the shape of their container
Gases - take the volume and shape of their container

Question 14

What are the metric system prefixes and their abbreviations? What does each prefix represent numerically?

Answer 14

Kilo- (k) 1,000
Hecto- (h) 100
Deca- (da) 10
Base Units - grams (g), meters (m), liters (L) 1
Deci- (d) 0.1
Centi- (c) 0.01
Milli- (m) 0.001

Question 15

Convert the following measurements:
5.27 g =into mg

Answer 15

5,270 mg

Question 16

Convert the following measurements:
405,200 km = into m

Answer 16

405,200,000 m

Question 17

Convert the following measurements:
12.6 L =into ml

Answer 17

12,600 mL

Question 18

Convert the following measurements:
0.000239 mg =into kg

Answer 18

0.000 000 000 239 kg

Question 19

Convert the following measurements:
23.4 cm = into m

Answer 19

0.234 m

Question 20

What are the rules for completing math problems and recording your answers with the proper number of significant digits?

Answer 20

When multiplying and dividing, the number of significant digits in the answer should equal the least amount of significant digits in the problem.
When adding and subtracting, the last significant digit in your answer should be in the same place as the least specific (or furthest to the left) place from the problem.

Question 21

Complete the problems below. Record your answers with the proper number of significant digits.
25.2 + 110

Answer 21

25.2 + 110 = 135.2 = 140

Question 22

Complete the problems below. Record your answers with the proper number of significant digits.
0.0034 x 0.5

Answer 22

0.0034 x 0.5 = 0.0017 = 0.002

Question 23

Complete the problems below. Record your answers with the proper number of significant digits.
100.0 - 22.0

Answer 23

100.0 - 22.0 = 78 = 78.0

Question 24

Complete the problems below. Record your answers with the proper number of significant digits.
212 / 50

Answer 24

212 / 50 = 4.24 = 4

Question 25

Complete the problems below. Record your answers with the proper number of significant digits.
2,100 x 42

Answer 25

2,100 x 42 = 88,200 = 88,000

Question 26

Complete the problems below. Record your answers with the proper number of significant digits.
0.053 / 0.00432

Answer 26

0.053 / 0.00432 = 12.2685 = 12

Question 27

2.53 x 10-7 L
Scientific Notation-Decimal Notation

Answer 27

0.000 000 253 L

Question 28

413,000 mL
Decimal Notation-Scientific Notation

Answer 28

4.13 X 105 mL

Question 29

0.00300 g
Decimal Notation-Scientific Notation

Answer 29

3.00 X 10-3 g

Question 30

Scientific Notation-Decimal Notation
2.15 x 106 s

Answer 30

2,150,000 s

Question 31

What is the formula for density? What are the units for density?

Answer 31

Density is mass divided by volume. The units are typically grams/milliliters or g/mL.

Question 32

A piece of metal weighs 0.594 kg and has a volume of 1.2 L.
Convert the mass of the metal to grams.

Convert the volume of the metal to mL.

Find the density of the metal in g/mL.

Answer 32

Convert the mass of the metal to grams.
594 g
Convert the volume of the metal to mL.
1,200 mL
Find the density of the metal in g/mL.
Density = 594 g/1,200 mL = 0.495 g/mL = 0.50 g/mL