Scientific Method
What is a hypothesis?
A reasonable and testable explanation for observationbs
What is energy?
The ability to do work
What is accuracy?
How close a measurement is to the true or actual value
Leading zeroes and trailing zeroes without a decimal are always __________________________
Not significant
What is heat?
The energy transferred between objects that are at different temperatures
What is an independent variable?
It is what is being tested or changed during the experiment
What does the Law of Conservation of Energy state?
Energy cannot be created or destroyed - it can only change forms
What is precision?
How close several measurements are to each other
Nonzero numbers, captive zeroes, and trailing zeroes with a decimal are always _____________________
significant
Heat always travels from _______ to ________
warm to cool
high heat to low heat
What is a dependent variable?
It is what is being measured at the end of an experiment; it depends on the independent variable
Give an example of an energy conversion using an everyday example
Ex. plugging in a lamp turns electrical energy into light energy
Ex. eating food turns chemical energy into mechanical or kinetic energy
Ex. pulling back and releasing an arrow turns potential energy to kinetic energy
Other examples are acceptable
What is 1.34 x 10-5 written in standard form (normal numbers)?
0.0000134
How many significant figures are in the number 12,040 ?
4
What is temperature?
The average kinetic energy of a substance
What is the difference between a scientific theory and a natural law?
A theory is a well-tested explanation of events while a law is description of events that has never been disproven
Give an example of an endothermic reaction
Ex. melting an ice cube
Ex. baking a cake
Ex. photosynthesis
Any example when heat is absorbed
What is 6,470,000 written in scientific notation?
6.47 x 106
Answer the following in the correct number of significant figures:
7.502 + 0.0009
7.503
(remember: when adding or subtracting, only pay attention to the number of decimal places)
Calculate the heat energy required for the following: (HINT: Pay attention to significant figures)
10.0 grams of water with a heat capacity of 4.184 J/gC are heated from 80oC to 100oC.
q = mCAT
q = (10 grams)(4.184 J/gC)(100-80)
q = (10 grams)(4.184 J/gC)(20)
q = 836.8 J
With correct significant figures: q = 800 J
What are the 6 steps of the scientific method in order?
Observe and Question
Research
Hypothesize
Experiment
Analyze Data and Form Conclusions
Report Results
Give an example of an exothermic reaction
Ex. a fire
Ex. digestion
Ex. freezing water
Any example where heat is released is ok
What is 3.5081 x 103 written in standard notation (normal numbers)?
3,508.1
Answer the following in the correct number of significant figures:
7.502/0.0009
8,000
(remember: when multiplying or dividing, pay attention to the total number of significant figures)
What is specific heat?
The quantity of the energy as heat that must be transferred to raise the temperature of 1 gram of a substance by 1 Kelvin