Chem Unit 1

Define matter

anything that has mass and takes up space

Define mass

the amount of matter in an object

Define weight

the measure of both an object's mass and the pull of gravity on it

Define chemistry

the study of matter and the changes it undergoes

Define substance

matter that has a uniform and definite composition

Define ozone

a chemical in the earth's atmosphere that absorbs most of the UV radiation

How is ozone formed?

when oxygen gas is exposed to UV radiation from the sun in the upper layer of the stratosphere

Why is protection from UV radiation neccesary?

to protect your skin from being burned or damaged, or getting skin cancer

What is another name for the thinning of the ozone layer?

the ozone hole

T/F? CFC is another name for chlorofluorocarbon

true

What is another name for CFCs?

chloroflourocarbons

T/F: CFC's are made up of carbon, fluorine, and cesium.

false

What is CFC made of?

chlorine, flourine, and carbon

T/F: all CFCs are synthetic chemicals

true

What is a synthetic chemical?

man made chemical

T/F: CFCs were developed as replacements for toxic refrigerants

true

Define macroscopic

things that can be seen with the naked eye

Define microscopic

things that can only be seen with the help of a microscope

Define submicroscopic

things that can not be seen even when using a microscope

List three things that are not matter

sound, light, heat (or thoughts, emotions)

Give an example of subatomic particles

atoms

List the five branches of chemistry

organic, inorganic, physical, analytical, biochemistry

T/F: the mass of an object can vary with the object's location

false

T/F: a mass measurement includes the effect of Earth's gravitational pull on the object being measured

false

T/F: scientists measure the amount of matter in terms of mass

true

T/F: subtle differences in weight exist at different locations on earth

true

T/F: your mass on the moon would be smaller than your mass on earth

false

T/F: mass is consistent

true

Define scientific method

an organized process used by scientists to do research, and to verify the work of other scientists

Define qualitative data

information that describes color, odor, shape, or other physical characteristics

Define quantitative data

nummerical information like temperature, pressure, volume, weight, or mass

Define hypothesis

an educated guess or a testable, tentative prediciton/statement about what has been observed

Define experiment

controlled observations that test a hypothesis

Define independent variable

the variable the experimenter plans to change

Define dependent variable

the variable whose value depends on the independent variable

Define control

a known standard for comparison

Define conclusion

a judgement based on the information obtained

Define theory

an explanation that has been supported by many experiments, but can still be revised or updated

Define scientific law

a relationship in nature that is supported by many experiments

List the four steps of the scientific method in order

observation, hypothesis, experiment, conclusion

What are the two types of observations a scientist can make?

qualitative and quantitative

What are the layers of the atmosphere in order from closest to the surface to farthest?

troposphere, stratosphere, mesosphere, thermosphere, exosphere