Chem 1020 - Chapter 2 Review Question with
Verified Correct Answers
Why is it necessary to include units when reporting scientific measurements?
1 Inch, for example, is far different from 1 Meter. Without units, we have no reference.
Numbers are arbitrary in Chemistry while units give those numbers meaning.
Why are the number of digits reported in scientific measurements important?
The number of digits indicates the precision of our measurement. More digits equals more
precision.
Why is scientific notation useful?
Scientific notation makes the equations easier to read given its compact nature and also saves
space.
If a measured quantity is written correctly, which digits are certain? Which are
uncertain?
Every digit except the last digit is certain. The last digit is estimated.
When do zeros count as significant digits and when don't they count?
Zeros to the left of the first "non zero number" do not count. The rest do.
How many significant digits are there in exact numbers?
There are an infinite amount. For example, 1 Meter is equal to 1.000000000... on into
infinity.
What limits the number of significant digits in a calculation involving only
multiplication and division?
, Your final answer should have the same amount of SF's as the figure with the least of amount
of SF's when you're multiplying or dividing.
What limits the number of significant digits in a calculation involving only addition and
subtraction?
Addition and subtraction are different from multiplication and division. When you adding or
subtracting, your final answer will have as many decimal places as the figure with the least
amount of decimal places.
How do we determine significant figures in calculations involving both
addition/subtraction and multiplication/division?
In calculations involving both multiplication/division and addition/subtraction, do the steps in
parentheses first; determine the correct number of significant figures in the intermediate
answer; then do the remaining steps.
What are the basic SI units of length, mass, and time.
Meters, kilograms, and seconds.
List the common units of volume.
Liter (L), Gallon (gal)
What is the difference between mass and weight?
Mass is how much matter is in an object while weight is how much gravity is pulling down
on that object. Your mass on earth and your mass on the moon stays the same, but your
weight will be very different since the moon has a very light gravitational pull.
What is a conversion factor?
Verified Correct Answers
Why is it necessary to include units when reporting scientific measurements?
1 Inch, for example, is far different from 1 Meter. Without units, we have no reference.
Numbers are arbitrary in Chemistry while units give those numbers meaning.
Why are the number of digits reported in scientific measurements important?
The number of digits indicates the precision of our measurement. More digits equals more
precision.
Why is scientific notation useful?
Scientific notation makes the equations easier to read given its compact nature and also saves
space.
If a measured quantity is written correctly, which digits are certain? Which are
uncertain?
Every digit except the last digit is certain. The last digit is estimated.
When do zeros count as significant digits and when don't they count?
Zeros to the left of the first "non zero number" do not count. The rest do.
How many significant digits are there in exact numbers?
There are an infinite amount. For example, 1 Meter is equal to 1.000000000... on into
infinity.
What limits the number of significant digits in a calculation involving only
multiplication and division?
, Your final answer should have the same amount of SF's as the figure with the least of amount
of SF's when you're multiplying or dividing.
What limits the number of significant digits in a calculation involving only addition and
subtraction?
Addition and subtraction are different from multiplication and division. When you adding or
subtracting, your final answer will have as many decimal places as the figure with the least
amount of decimal places.
How do we determine significant figures in calculations involving both
addition/subtraction and multiplication/division?
In calculations involving both multiplication/division and addition/subtraction, do the steps in
parentheses first; determine the correct number of significant figures in the intermediate
answer; then do the remaining steps.
What are the basic SI units of length, mass, and time.
Meters, kilograms, and seconds.
List the common units of volume.
Liter (L), Gallon (gal)
What is the difference between mass and weight?
Mass is how much matter is in an object while weight is how much gravity is pulling down
on that object. Your mass on earth and your mass on the moon stays the same, but your
weight will be very different since the moon has a very light gravitational pull.
What is a conversion factor?
