Chemistry - the study of matter and the energy used to change it
Matter- anything that has mass and volume
-Composed of elements
Elements- cannot be simplified
periodic table- lists all known elements
Atoms- smallest functional unit of elements
- Nucleus (central core)
o Protons
▪ Have a positive charge
▪ Have mass
o Neutrons
▪ No charge
▪ Have mass
- Shells (surrounding nucleus)
o Electrons
▪ Negative charge
▪ No discernable mass
- Colossians 1:17 explains why atoms are able to stay together while repelling
themselves
- Atomic symbol- one or 2 letters
- Atomic number- number of protons (and electrons before a reaction)
- Atomic mass- roughly equal to protons + neutrons
- In an electrically neutral atom, number of protons = number of electrons
o First shell- 2 electrons
o Second shell- eight electrons
o Third shell- eighteen electrons
o To be electronically stable, there has to be 18 on the outer shell or 8
- Isotopes have a different number of neutrons
o Same atomic number (same number of protons)
o Different atomic mass (different number of neutrons)
o Unstable isotopes are called radioisotopes
o Radioisotopes give off
▪ Energy (in the form of radiation)
▪ Particles
- Some radio isotopes have scientific and medical uses
o Carbon 14 used for dating fossils
o Diagnostic imaging
o Cancer treatment
o Power supply for implants such as cardiac pacemakers
, BIOL 102 Notes PT 3
Dr. Terry Spohn-Liberty University
The importance of Hydrogen Ions:
• Acids
o Donate H ions (protons)
o Increase H ion concentration in solutions
• Bases
o Accept H ions
o Lower H ion concentration in solution
• pH scale
o a measure of hydrogen ion concentration
o acids have a pH less than 7
o bases have a pH greater than 7
Buffers
• minimize pH change
• help maintain stable pH in body fluids
• aroi aid ad iaroate at as oe of the ody’s ost iportat uffer pairs
• weak acids stay in water
Organic Molecules of Living Organisms
• carbon- the building block if living things
o comprises 18% of the body by weight
• can form 4 covalent bonds
• can form single or double bonds
• can build micro or macromolecules
Macromolecules are synthesized and broken down in the cell
• dehydration synthesis
o removes equivalent of a water molecule to link molecular units
o requires energy
o builds macromolecules from smaller subunits
• Hydrolysis
o Adds the equivalent of a water molecule to break apart macromolecules
o Releases energy
• Dehydration synthesis is the reverse of hydrolysis
Carbohydrates: used for energy and structural support
• Monosaccharides: simple sugars
o Glucose
o Fructose
o Galactose
,o Ribose
o Deoxyribose
, BIOL 102- Dr. Spohn Liberty University
Chapter 1 pt 2
• Energy- the capacity to do work
• Potential energy- stored energy
• Kinetic energy- energy in motion, energy doing work
• Electrons have potential energy
o Each shell corresponds to a specific level of potential energy
o Shells further from the nucleus contain electrons with more potential energy
• Atoms are more stable when the outer shell is full
• Atoms will interact with other shells to fill outer shell
• Chemical bonds link atoms to form molecules
o Chemical bonds- attractive forces holding atoms together
o Kinds of chemical bonds
▪ Covalent bonds
▪ Ionic bonds
▪ Hydrogen bonds
o Strength of a bond determined by amount of energy it takes to break it
• Molecule- 2 or more atoms chemically bonded together
• Compound- 2 or more different atoms chemically bonded together
• Covalent bonds form when atoms share electrons
o Very strong bonds
o H2, O2, H2O
• Nonpolar covalent bonds- electrons shared equally
• Polar covalent bonds- electrons not shared equally
• Ionic bonds
o Ion- an electrically charged atom or molecule
o Positively charged ion forms if an electron is lost
o Negatively charged ion forms if an electron is gained
o Ionic bond- attractive force between oppositely charged ions
• Hydrogen bonds
o Form between polar molecules
o Polar molecules:
▪ Contain polar covalent bonds in which there is unequal sharing of
electrons
▪ Electrically neutral overall, but uneven charge distribution
o Hydrogen bonds
▪ Weak attraction between oppositely charged regions of polar molecules
▪ Ex. Weak forces between water molecules
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller anyiamgeorge19. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $14.99. You're not tied to anything after your purchase.