review question: 
what is meant by the half life of an isotope? explain how isotopes are clinically useful.

Bonding:

atoms creating molecules

 2. Covalent Bonds

= partial charge

 General Chemistry

FYI... Carbon-14 decays into nitrogen-14 through a process called beta decay...a neutron within the carbon-14 nucleus transforms into a proton, an electron, and an electron antineutrino. This process increases the atomic number of the element from 6 (carbon) to 7 (nitrogen), while the mass number remains 14. 

Oxygen exhibits a partial negative charge  Hydrogen exhibits a partial positive charge. 

if one atom is highly electronegative and the other less electronegative, the covalent bond will be polar

Bonding Types:
​1. Ionic                    2. Covalent            3. Hydrogen

 Carbon

C and H have similar electronegativity

         electrons are evenly shared

 diagnostics: 
 *techniques like PET scans and bone scans to visualize internal organs, tissues, and structures,              aiding in the detection of tumors, infections, abnormalities.
 *tracer studies to track the movement and metabolism of isotope labelled molecules.
treatment: 
 * radiation therapy to deliver targeted doses of radiation to kill cancer cells and shrink tumors.
 * certain isotopes treat specific conditions like hyperthyroidism. isotopes are taken up by the thyroid gland and destroy overactive cells. 

   There can be strong or weak acids and bases...
HCl is a strong acid because it dissociates almost completely in water releasing H+. 
Acetic acid (CH3COOH...vinegar is 6% acetic acid in water) is a weak acid because it does not dissociate well in water.

Bases containing OH- are considered strong, like ​NaOH, because they also dissociate almost completely but they release OH-. what does that do to the pH? Why?

    ​    3. Hydrogen Bonds

review question: 
describe the structure of an atom. explain why atoms bond with one another.

    1. ionic bonds

 A solvent is a substance that dissolves  solute particles.
​  A solute is a substance that is dissolved by a solvent.

 The outermost orbital shell of an atom is called its
​valence shell.
the electrons in the valence shell are valence electrons.

​Valence electrons are the highest energy electrons in an atom and are therefore the most reactive.

OH-
​ is a hydroxyl group

  this sets up partially charged
​"poles" in the molecule.

   isotopes

review question: 
what is an ion? how are ions made? why do ions bond together?

 Na (sodium) atomic number = 11

  Cl (chlorine) atomic number = 17  

is it just about H+?

review question: 
water is a universal solvent. why is this so important referencing living organisms?

    ​       pH

at pH 7
H+ and OH- concentrations are =

  properties of water

 Hydrogen bonds have about a tenth of the strength of an average covalent bond

clinical uses of radioisotopes

review question: 
explain why the disassociation of water is an important factor in the pH of a solution.

 Electron orbitals 
 predict where an electron might be at any given time.   The number of orbitals increases as the atomic number increases. 

octet rule:
atoms tend to gain, lose, or share electrons in order to achieve a full outer electron shell with eight valence electrons ibn order to achieve a stable electron configuration.

 hydrogen bonds are strong intermolecular forces created when a hydrogen atom bonded to an electronegative atom (polar covalent bond)  is attracted to a nearby electronegative atom. 

   It is important for cells/tissues maintain pH homeostasis.
The pH of the human body ranges between 7.35 to 7.45, with the average at 7.4  

Oxygen is more electronegative than H

         electrons are unevenly shared

   nonpolar covalent bonds

An element's
​atomic number (#protons/# electrons)   is the number listed here at the upper left of each symbol. The atomic mass (#protons + # neutrons) is the number listed below the symbol.

pH 3  10*-3
​ has more H+ than pH 6  10*-6

in an aqueous solution,
​as H+ concentration increases, OH- concentration decreases.

as just discussed, ​Carbon (C) has an atomic number  = 6 
atomic mass = 12.01

review question: 
how is a polar covalent bond different from a non-polar covalent bond?
explain what causes atoms to engage in a polar covalent bond.

​Carbon (C) has an atomic number or 6 and an atomic mass of 12.01

Hydrogen Bonds can only occur between two polar molecules. Why?

 Carbon-14 
​is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Every 5,730 years, the radioactivity of carbon-14 decays by half which is called its half-life, a fact used during Carbon Dating.

   isotopes are variations of elements that have the same number of protons but different numbers of neutrons. 

   The pH scale measures how much H+ is in a solution.
A lot of Hydrogen = low pH # = an acidic solution = an acid
less H+ = a higher pH = a basic (alkaline) solution = a base

  polar covalent bonds

   what do the pH numbers really mean?

review question: 
in order for a hydrogen bond to occur between two molecules, both molecules  must contain polar covalent bonds. ​ explain why. 

review question: 
when dissolved in water...
citric acid has a pH of 3.
​oxalic acid has a pH of 4
referencing the meaning of the pH numbers, explain which acid donates more H+ to the solution.

   next up...
​biologically relevant molecules ;)