Chapter 0a Flashcards
work in crime laboratories where they analyeze bodily fluids and tissue samples collected by the crime scene investigators
forensic scientists
- study of composition, structure, properties, and reactions of matter
- happens all around you every day
chemistry
undergo a chemical reaction when dropped in water
antacid
another word for all substances that make up our world
matter
- substances that have the same composition and properties wherever found
- often substances made by chemists that you use everyday
chemicals
chemicals in toothpaste
- calcium carbonate
- sorbitol
- sodium lauryl sulfate
- titanium dioxide
- triclosan
- sodium fluorophosphate
- methyl salicylate
used as an abrasive to remove plaque
calcium carbonate
- prevents loss of water and hardening of toothpaste
- sweetener
sorbitol
used to loosen plaque
sodium lauryl sulfate
makes toothpaste white and opaque
titanium dioxide
inhibits bacteria that cause plaque and gum disease
triclosan
prevents formation of cavities by strengthening tooth enamel with fluoride
sodium fluorophosphate
gives toothpaste a pleasant wintergreen flavor
methyl salicylate
does the sunlight contain chemicals
no. it is energy
probably best known for working out the nature of the chemical bond
Linus Pauling
set of general principles that helps to describe how a scientist thinks
scientific method
steps in scientific method
- observations
- hypothesis
- experiments
- conclusion
modified if the results of the experiment do not support it
hypothesis
identify:
during your visit to the gym, your trainer records that you ran for 25 minutes on the treadmill
observation
identify:
scientific studies show that exercising lowers blood pressure
conclusion
identify:
your doctor thinks that your weight loss is due to increased exercise
hypothesis
average number of hair on scalp
1 x 10^5 hairs
approx. width of hair
8 x 10^-6 m
two parts of the scientific notation
- coefficient
- power of 10
greater than 1
positive
less than 1
negative
guide to writing a number in scientific notation
- move decimal point to obtain a coefficient that is at least 1 but less than 10
- express number of places moved as power of 10
- write the product of coefficient multiplied by power of 10
write in scientific notation:
64 000
6.4 x 10^4
write in scientific notation:
0.021
2.1 x 10^-2