Welcome to Dr. Kate Kraus Brilakis' Learning Portal
Bonding:
atoms creating molecules
2. Covalent Bonds
= partial charge
General Chemistry
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.
HCl is a strong acid because it dissociates almost completely in water releasing H+.
Acetic acid (CH3COOH = vinegar is 6% acetic acid) is a weak acid because it does not dissociate well in water.
3. Hydrogen Bonds
isotopes are variations of elements that have the same number of protons but different numbers of neutrons.
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
Na (sodium) atomic number = 11
Cl (chlorine) atomic number = 17
is it just about H+?
pH
at pH 7
H+ and OH- concentrations are =
Bases like NaOH containing OH- are considered strong because they also dissociate almost completely releasing OH-.
what does that do to the pH?
properties of water
Hydrogen bonds have about a tenth of the strength of an average covalent bond
clinical uses of radioisotopes
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.
polar covalent bonds
vs
non-polar covalent bonds
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.
There can be strong or weak acids and bases
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.
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?
next up...
biologically relevant molecules ;)