Chapter 2 Review Flashcards
what is the capacity to do work?
energy
The change in matter from one form to another without a change in chemical properties is a _____ change
physical
A change that occurs when one or more substances change into new substances with different properties is a ______ change
chemical
A change in matter in which energy is absorbed is a(an) _______ process
endothermic
A change in matter in which energy is released is a(an) _______ process
exothermic
To freeze a substance, energy must be ____ from the substance
removed
Energy must be added to a solid to melt it. This addition gives the particles ___ energy allowing them to move out of the crystalline structure.
heat
state the law of conservation of energy
the total energy of an isolated system cannot change; can only change from form to form
What is heat?
The energy transferred between objects that are different temperatures. Always transferred from high to low temperatures
Define temperature
Temperature is a measure of the average kinetic energy of the particles in an object
What is the difference between temperature and heat?
Temperature is how hot or cold something is. Heat is energy transferred between two objects at different temperatures
What is the celsius conversion equation?
C= K-273
What is the kelvin conversion equation?
K= C+273
Define specific heat.
The energy is takes to raise 1 gram of of the substance by 1 degree Celsius
What is the difference between accuracy and precision?
Accuracy is how close a measurement or set of measurements are to the true value. Precision is the exactness of a measurement.
What is a model?
A model is a tool in science used to help describe objects, systems, or ideas that are too large, too small, too complex, too expensive, or too dangerous to experiment with directly
Why are models useful in chemistry?
Chemists use models to try and explain their observations as they formulate theories
law of conservation of mass
the products of a chemical reaction have the same mass as the reactants
What is a hypothesis?
a reasonable and testable explanation of observations
What is the scientific law?
a well-tested explanation for a phenomenon based on observation, experimentation, ad reasoning
What are the fundamental procedures in the scientific method?
observe, ask a question, form a hypothesis, experiment, analyze data, conclusion, report findings
When performing an experiment, why is it important to have control?
Controls allow the experimenter to minimize the effects of factors other than the one being tested.
What is a variable?
a factor in a scientific experiment that may be subject to change
Why is it important to publish the results of research findings?
It provides instructions so that other researchers can repeat the experiment or build on it to verify and confirm the results.
potential energy
the energy started within a system
kinetic energy
the energy of an object that is due to the object’s motion
endothermic reaction
process in which heat is being absorbed from the environment
exothermic reaction
a system releases heat into the environment
what is science?
an attempt to explain how things in the natural world work
independent variable
the variable the experimenter chooses to change
dependent variable
changes in response to the manipulated variable
theory
an attempt to explain the cause of something in the natural world
define law
describes a behavior in the natural world that is always true
what is high heat capacity?
a substance requires more energy to heat up
what is low heat capacity?
energy(heat) travels through a substance easily
