GENERAL CHEMISTRY 1: Chemical Foundations Flashcards
The sample corresponds to Chapter 1: Chemical Foundations for General Chemistry I.
What is Chemistry?
Chemistry is the study of the composition of matter, its
properties, and the changes it undergoes. Chemistry aims to connect the macroscopic behavior of matter we observe to the microscopic behavior of atoms and molecules.
What is a hypothesis?
A hypothesis is a tentative explanation for an observation.
What is a theory?
A theory (also referred to as a model) is a set of tested hypotheses that gives an overall explanation of some natural phenomenon. A theory attempts to explain why something happens.
What is a law?
A law is a summary of measurable behavior and summarizes what happens. A law will usually be supported by a mathematical expression.
A ______________ is best described as an educated guess.
A hypothesis is best described as an educated guess.
What is the fundamental difference between a theory and a law?
A law will summarize a series of related observations, while a theory will explain the underlying reasons for them.
A law is the “what” whereas a theory is “why.”
True or False:
Both a theory and a hypothesis can be supported or not supported by experiments.
True
What is a qualitative observation?
Qualitative observations are descriptive and do not involve a number.
What is a quantitative observation?
Quantitative observations answer the question “how much?” and involve both a unit and a number.
Which of the following statements could be described as an observation?
Cats are the best animal.
Cats cannot bark.
People who do not like cats are the worst.
Cats are the best animal. = Opinon, not an observation.
Cats cannot bark. = Observation
People who do not like cats are the worst. = Opinon, not an observation.
True or False:
“My Chemistry class has more students than your Chemistry class” is an example of a quantitative observation.
False: This would be a qualitative statement.
Remember that quantitative observations must contain a number and a unit
What are the SI units for mass, length, and time, respectively?
The SI unit for mass is the kilogram (kg).
The SI unit for length is meter (m).
The SI unit for time is second (s).
What are the SI units for electric current, amount of substance, and luminous intensity, respectively?
The SI unit for electric current is ampere (A).
The SI unit for amount of substance is the mole (mol).
The SI unit for luminous intensity is the candela (cd).
True or False:
The SI unit for temperature is kelvin (K)
True
Convert 6755 into standard scientific notation.
Convert 0.00000756 into standard scientific notation.
Provide the correct abbreviations for each of the following units of measurement: milliliter, nanosecond, picometer, and microgram.
millilter = mL
nanosecond = ns
picometer = pm
microgram = μg
1 dm = ??? m
1 m = ??? dm
dm = decimeter
1 cm = ??? m
1 m = ??? cm
cm = centimeter
1 mg = ??? g
1 g = ??? mg
mg = milligram
1 μm = ??? m
1 m = ??? μm
μm = micrometer
1 ns = ??? s
1 s = ??? ns
ns = nanosecond
1 pg = ??? g
1 g = ??? pg
pg = picogram
1 fs = ??? s
1 s = ??? fs
fs = femtosecond
1 hm = ??? m
1 m = ??? hm
hm = hectometer
1 kg = ??? g
1 g = ??? kg
kg = kilogram
1 Mg = ??? g
1 g = ??? Mg
Mg = Megagram
1 Gg = ??? g
1 g = ??? Gg
Gg = gigagram
What is the difference between mass and weight?
Mass describes the quantity of matter contained within a object.
Weight has to do with the force of gravity acting on an object and is proportional to the mass of an object.