Measurement
Find the average of these three values:
35 cm, 45 cm, 31 cm
31 + 45 + 35 = 111
111/3 = 37cm
Name two instances in which dimensional analysis could be helpful.
1. Baking or cooking
2. Traveling
3. Building/ engineering
What is an observation based on?
Your senses
Write out an example with any number written in proper scientific notation (the exponent can be positive or negative, doesn't matter)
Varies, approved by teacher
Which division of matter CAN be physically separated?
Mixture
Qualitative- qualities, characteristics, traits
Quantitative- numbers, measurements, quantities
In what 2 ways could you write the following conversion factor?
60 minutes = 1 hour
60 mins/ 1 hr
1 hr/ 60 mins
What is mass?
The amount of matter in an object.
Complete the sentences:
If you started with a big number, your exponent is ___.
If you started with a small number or decimal, your exponent is ____.
Big number = positive exponent
Small number = negative exponent
What do extensive properties depend on?
Depends on the amount of matter that is present.
Give me the difference between accuracy and precision.
Accuracy: how correct and close to the truth.
Precision: how specific is a measurement or consistent. How repeatable.
How many feet are in 411 cm?
13.5 ft
What are atoms?
Atoms are the smallest unit of an element. "Building block"
Convert 0.0098 to scientific notation.
9.8 x 10 ^-3
Which of the following is NOT an example of an intensive property?
a. Mass b. Density c. Specific Heat d. Boiling Point
How many kilograms are there in 12,138 mg?
0.012138 kg
How many inches are in 500 yards?
18,000 inches
Tell me the difference between an element and a compound. Give an example of both.
An element is a pure substance. Ex.) anything on the periodic table
A compound is a combination of 2 or more different elements. Ex.) Water, glucose, NaCl
Convert 3.1 x 10^-4 to the standard notation.
0.00031
Name three things that you could observe during a chemical reaction.
Any of these: release of light, temperature change, color change, odor change, gas given off, precipitate formation.
What are the two instances in which zeros count for significant figures?
1. Trailing zeroes when a decimal is present. (ex. 0.500- 3 sig figs)
2. Sandwiched zeroes (404 - 3 sig figs)
Dimensional analysis could help us make conversions between the ______ and _______ systems.
(Name the two systems)
Customary // Metric
Tell me the difference between heterogenous and homogenous mixtures. Give an example of each.
Heterogenous mixtures: variable composition, tend to separate out. Ex.) paint, salad dressing, blood
Homogenous mixtures: even composition, appear blended. Ex.) alloy, aqueous solution, lemonade, Kool- aid, bleach, 14K gold, stainless steel
Give me one good reason as to why we should use scientific notation when working in chemistry.
Varies, approved by teacher
True or False: The Law of Conservation of Matter states that matter is created or destroyed, but it does not change forms.
False.