Definitions
Definition of Chemistry
What is the science that seeks to understand the behavior of matter by studying the behavior of atoms and molecules?
A scientific theory is the _____ things in nature are the way they are and behave the way they do. A scientific law is the _____.
What is a scientific theory is the why, and a scientific law is the how?
Mixtures are
What is a matter that consists of two or more substances that are physically mixed (not chemically combined)?
Different samples have different characteristics.
The metric base unit of finding the length of something.
What is meters?
True/False: Ice is more dense than Ethanol.
What is True?
Bonus 100 points: Ethanol is 0.789 g/cm^3 vs. Ice is 0.917 g/cm^3
Definition of Matter
What is anything that has mass and occupies space?
Chemicals are substances that always have the _____ and ______.
What is chemicals are substances that always have the same composition and properties?
Pure Substances are
What is made up of one type of molecule or atom, and all samples have the same characteristics?
A base unit that you measure energy with.
What is a calorie (cal)?
True/False: Table salt (sodium chloride) is less dense than sugar (sucrose).
What is False?
Bonus 100 points: Table salt is 2.16 g/cm^3 vs. sugar is 1.58 g/cm^3
Definition of Scientific Law
What is the statement that summarizes all past observations and predicts future observations?
The universe consists of ____, ____, and ____.
What is the universe consists of matter, energy, and empty space?
True/False: Pure Substances consist of elements and compounds. Most natural pure substances are elements.
What is false?
Explanation: Pure substances do consist of elements and compounds, but the most natural pure substances are compounds.
A mass that is 1000000 times greater than 1 gram.
What is a megagram?
"Density is the heart of chemistry."
Explain
What is when you write density = a heart, you put a line through the middle and see an M on the top and a V on the bottom. This helps others know that Density = Mass over Volume (D=M/V).
Definition of Distillation
What is when a mixture of liquids with different boiling points is heated; the most volatile component boils first, and the vapor is then cooled and collected as a pure liquid?
_____ takes the shape of the container and fills the volume of a container.
What is gas?
True/False: Heterogeneous mixtures have a uniform composition throughout, while homogeneous mixtures do not.
What is false?
A unit of time that is 1/1000000000 of a second.
What is a nanosecond?
What is the density in g/cm^3 of 32.3g of metal if the level of water in a graduated cylinder rises from 15.01mL to 24.17mL after the metal is added?
What is
24.17-15.01= 9.16mL
D= Mass/Volume= 32.3g/9.16mL= 3.53g/mL
Since 1mL= 1 cm, the final answer is 3.53g/cm^3
Purpose of the Scientific Approach to Knowledge
What is scientists try to understand the universe through empirical knowledge gained from observation and experiment?
Bonus 100 points: Some observations are qualitative (descriptions or categorizing) and others are quantitative (compare a characteristic to a standard numerical scale). Observations often lead to hypotheses!
Particles that are randomly distributed without any long-range pattern are _____.
Examples are ____, _____, and _____(dicussed in class).
What is particles are randomly distributed without any long-range pattern are Amorphous solids?
Examples are glass, plastic, and charcoal.
1. Air is a pure substance or a mixture
2. Air is a compound, element, heterogenous mixture, or homogeneous mixture
Explain why
1. What is a mixture?
2. What is a homogenous mixture?
Explanation: Air consists of different particles such as oxygen, carbon dioxide, water vapor, dust, etc., which makes it a mixture. Air is homogeneous because it has a uniform composition throughout, as everyone inhales and exhales the same air.
In a word problem, if you are given the Celsius temperature, what is the formula to find Fahrenheit?
What is TF= 1.8(TC) +32?
What volume of water will be displaced by 30g of silver (Density is 12.6g/mL)?
Round to the nearest tenth.
What is
D= M/V
V= M/D
V= 30g/12.6g/mL
V= 2.4 mL