Exam 1: Intro/Matter/Atoms Flashcards
What is the first scientific discipline with theoretical principals that are also applied to something?
Chemistry
What are 2 other examples of theoretical disciplines?
Physics and Math
Define chemistry
The study of matter and the changes it undergoes
T/F There is no crossover between different chemical disciplines
False
What do physical chemists focus on?
They are “overglorified” mathematicians; they want to understand chemical systems from a theoretical framework
What do analytical chemists study?
Study methods for identification and quantification of matter within a chemical system; everything they do is applied science but they also do some theoretical science as well
Ex: Using instruments and medical diagnostics like MRIs/CT scans/etc.
What do inorganic chemists study?
Substances that are derived from all of the elements EXCEPT carbon
What do organic chemists study?
Carbon-based compounds
What do biochemists study?
Chemical processes that occur within living systems
Define matter
Anything that has mass and occupies space
What comprises matter?
Everything
Describe the differences in shape between solids, liquids, and gases
Solids - defined shape
Liquids - less defined shape; requires a container
Gases - no shape whatsoever
What can we do to gases and somewhat do to liquids?
Compress them
What happens to the volume and pressure when you compress a liquid or gas?
Compression decreases the volume and increases the pressure
T/F When a cylinder of gas (that’s pressurized) goes empty, there is no more gas left in the cylinder
False; when the cylinder goes “empty” the pressure inside the take is equalized inside the tank vs outside of the tank but the gas is not entirely gone
What occurs when you continue to compress a gas?
It can liquify
Can you compress a liquid?
Yes, but not as much as gas
Can solids be compressed?
Not really; if you continue to compress a solid, you will just break it
Define atoms
Submicroscopic particles that are the fundamental “building blocks” of all matter (they can be the same type of different types combined)
What 3 things are found within an atom?
Protons, neutrons, electrons
What are the charges for protons, neutrons, and electrons?
Protons - positively charged
Neutrons - neutral
Electrons - negatively charged
What makes up most of the mass of an atom?
Protons and neutrons
Where are protons and neutrons found?
In the nucleus of the atom
Where are electrons found?
Surrounding the nucleus in orbitals in the electron cloud
How can we tell how many protons are in an atom?
Look at the atomic number; this number tells us the identity of the atom and thus the amount of protons
What does the amount of neutrons tell us?
The isotope of the element we are looking at
Why are isotopes important?
They are important because they can be used for looking for diseases
Ex: Using Iodine or Fluorine w/ scans to light up specific parts
What do electrons tell us about an atom?
Electrons tell us the charge of the atom
Can you change the charge of an electron?
Yes; by losing or gaining an electron, you can change whether it is positively/negatively charged
When you lose an electron = the charge becomes positive = CATIONS
Ex: Metals like to lose electrons
When you gain an electron = the charge becomes negative = ANIONS
Ex: Gases/Non-metals like to gain electrons
What are molecules?
Two or more atoms joined in a specific arrangement
What are pure substances?
Substance that is comprised of a single type of matter
What 2 things can pure substances be broken down into?
Elements - can not be broken down further
Compounds - can be broken down even further
What is a mixture?
Matter that consists of two or more pure substances
What are the 2 types of mixtures?
Homogenous mixture - mixture having a uniform composition and properties (same type of matter)
Heterogenous mixture - a mixture that is not uniform in composition and properties (different types of matter)
Is the air we breathe a pure substance or a mixture?
Mixture
Is the air we breathe a homogeneous or heterogeneous mixture?
Homogeneous mixture; when there is smog it becomes a heterogenous mixture
What is a physical change in matter?
A change that alters the state or appearance of matter, but not the composition
Ex: Chopping wood for a fire into smaller and smaller pieces
What are the 6 phase changes of matter?
- Melting (solid to a liquid)
- Freezing (liquid to a solid)
- Vaporization (liquid to a gas)
- Condensation (gas to a liquid)
- Deposition (gas to a solid) - water vapor to ice
- Sublimation (solid to a gas) - dry ice
What is a chemical change?
A change that alters the composition; atoms rearrange and create different substances
Ex: Iron rusting; exposure to air changes the molecules to have iron attached to oxygen and drastically changes the properties of a compound
Ex: Fire burning wood
What are physical properties of matter?
Properties displayed by a substance that does not cause a change in composition
Ex: Odor, taste, color, appearance, melting point, boiling point
What are chemical properties of matter?
Properties displayed by a substance caused by a change in its composition
Ex: corrosiveness, flammability, acidity, toxicity
