Density
Example Problems
One/Multi-Step Calculations
Scientific Notation
100
True or False: Density is an intensive property of matter
True
100
How many significant figures are in 2.5 x 10²?
2
100
What is the answer to this calculation?
12.721 - 1.30
11.42
100
What is the definition of an exponential?
"10ⁿ" 10 raised to an exponent
200
What's the formula for density? And what do the variables represent?
p = m/d
200
How many significant figures are in 3,200,200?
5
200
True or False: The rules for addition, subtraction, multiplication, and division are all the same when it comes to trailing zeros
False: Addition and subtraction have to do with the amount of decimal places in the equation whereas multiplication and division deal with the number of significant figures
200
Which way does the decimal point go if there is a negative exponent?
To the left
300
Which of the following best describes the concept of density?
a. Density is the weight be unit volume of a substance
b. Density is the volume per unit mass of a substance
c. Density is the force per unit area of a substance
d. Density is the mass per unit volume of a substance
D
300
21.4mL
300
Calculate this expression in the correct number of significant figures
(4.56 + 2.1) x 3.47
a. 23.8992
b. 23
c. 24
d. 20
b. 23
Why?
300
True or false:
A coefficient in proper scientific notation can have AT MOST 2 significant figures in front of the decimal place
False: Proper scientific notation has one digit in front of the decimal place, for example 4.65 x 102
400
Why does an object sink in water? Think about each formula.
a. The density of the object is less than the density of water
b. The object is hollow and filled with air
c. The object is made of a material that repels water
d. The density of the object is greater than the density of water
D
400
True or False: 3.46 x 10⁻⁵ in standard notation is 0.00000346
False, the superscript "-5" pushes the decimal point 5 spaces to the left, the correct standard notation is 0.0000346
400
See slide 6
Still 3, the significant figures from the given information does not change in the calculations. The significant figures also do not change if we use a conversion factor with a different amount of digits.
400
What is 3,454 in two significant figures?
3,500
500
How do we set up the equation to solve 1.900 km² in yards?
1.900 km² x (1.094yd/1m) x (10³m/1km)2 = 2.2274 x 106yd2
500
How many grams are in 7.7 x 10² kilograms?
7.7 x 10^5g
500
See slide 7
a. 0.021
Why?
500
How many significant figures are in the final answer? See slide 5
2
(2.4 x 10⁻⁴)