Chapter 0a

Question 1

work in crime laboratories where they analyeze bodily fluids and tissue samples collected by the crime scene investigators

Answer 1

forensic scientists

Question 2

• study of composition, structure, properties, and reactions of matter
• happens all around you every day

Answer 2

chemistry

Question 3

undergo a chemical reaction when dropped in water

Answer 3

antacid

Question 4

another word for all substances that make up our world

Answer 4

matter

Question 5

• substances that have the same composition and properties wherever found
• often substances made by chemists that you use everyday

Answer 5

chemicals

Question 6

chemicals in toothpaste

Answer 6

1. calcium carbonate
2. sorbitol
3. sodium lauryl sulfate
4. titanium dioxide
5. triclosan
6. sodium fluorophosphate
7. methyl salicylate

Question 7

used as an abrasive to remove plaque

Answer 7

calcium carbonate

Question 8

• prevents loss of water and hardening of toothpaste
• sweetener

Answer 8

sorbitol

Question 9

used to loosen plaque

Answer 9

sodium lauryl sulfate

Question 10

makes toothpaste white and opaque

Answer 10

titanium dioxide

Question 11

inhibits bacteria that cause plaque and gum disease

Answer 11

triclosan

Question 12

prevents formation of cavities by strengthening tooth enamel with fluoride

Answer 12

sodium fluorophosphate

Question 13

gives toothpaste a pleasant wintergreen flavor

Answer 13

methyl salicylate

Question 14

does the sunlight contain chemicals

Answer 14

no. it is energy

Question 15

probably best known for working out the nature of the chemical bond

Answer 15

Linus Pauling

Question 16

set of general principles that helps to describe how a scientist thinks

Answer 16

scientific method

Question 17

steps in scientific method

Answer 17

1. observations
2. hypothesis
3. experiments
4. conclusion

Question 18

modified if the results of the experiment do not support it

Answer 18

hypothesis

Question 19

identify:
during your visit to the gym, your trainer records that you ran for 25 minutes on the treadmill

Answer 19

observation

Question 20

identify:
scientific studies show that exercising lowers blood pressure

Answer 20

conclusion

Question 21

identify:
your doctor thinks that your weight loss is due to increased exercise

Answer 21

hypothesis

Question 22

average number of hair on scalp

Answer 22

1 x 10^5 hairs

Question 23

approx. width of hair

Answer 23

8 x 10^-6 m

Question 24

two parts of the scientific notation

Answer 24

1. coefficient
2. power of 10

Question 25

greater than 1

Answer 25

positive

Question 26

less than 1

Answer 26

negative

Question 27

guide to writing a number in scientific notation

Answer 27

1. move decimal point to obtain a coefficient that is at least 1 but less than 10
2. express number of places moved as power of 10
3. write the product of coefficient multiplied by power of 10

Question 28

write in scientific notation:
64 000

Answer 28

6.4 x 10^4

Question 29

write in scientific notation:
0.021

Answer 29

2.1 x 10^-2