Elements are more than one hundred substances that cannot be chemically interconverted or broken down into simpler substances and are primary constituents of matter. Each element is distinguished by its atomic number, i.e., the number of protons in the nuclei of its atom, also known as the basic unit of a chemical element. Protons are subatomic particles, which are particles smaller than an atom. Electrons, and neutrons are also examples of subatomic particles but they all have different charges. A proton has a positive charge, an electron has a negative charge, and a neutron has no charge. Molecules, also known as groups of atoms bonded together, form chemical compounds that take part in a chemical reaction. Molecules use bonds to form into compounds. An ionic bond is a chemical bond in which the atom transfers electrons while a covalent bond is a chemical bond in which the atoms share electrons. A chemical formula is a way of expressing the information about what makes up the compound. Two examples of compounds are organic compounds, and inorganic compounds. Organic compounds are made up of the elements carbon and hydrogen, while inorganic compounds have either of the elements, hydrogen and carbon. Macromolecules also known as “big molecules,” are made from thousands or even hundreds of thousands of even smaller molecules. Four examples of macromolecules are proteins, carbohydrates, lipids, and nucleic acids. Carbohydrates are made up of monosaccharides, simple sugar molecules that
Chem 220 Notes
Ch. 01 and 02: Structure and Bonding of Organic Molecules
I. Types of Chemical Bonds
A. Why do atoms forms bonds?
Atoms want to have the same number of electrons as the nearest noble gas atom (noble
gas configuration). This requires having a completely full or completely empty valence
shell of electrons.
Most main groups atoms will try to have eight valence electrons to completely fill their
valence shell; this is the octet rule. There are some exceptions: hydrogen…
CHEM 251 EXAM 1 REVIEW
Chapter 1 – 60 points
Definition of organic compounds-two main elements-why carbon is so important
Organic compounds or organic molecule is a chemical which mainly contains carbon, forming carbon-carbon bonds and carbon-hydrogen.
Carbon is the key for:
-Diversity of compounds possible thanks to forms chaims easily
-Forms 4 covalent bounds, especially other carbom atoms and can form chains of carbom atoms with very strong bonds.
-Is a small atom.…
January 28th, 2015
CHEM 237 – Organic Chem Lab
TLC Analysis of Analgesic Drugs
1. Once 2 TLC plate were obtained, a line about 1 cm from the bottom (solvent line) and from the top (solvent front) of the plate was drawn using a dull pencil on the side that has the silica (DON’T use ink!). A developing chamber was obtained with 5 mL of the TLC developing solvent, which was already pre made, poured inside. The depth of the solvent was no more than 0.5 cm or…
CHEM 220B: Organic Chemisty
Formerly used to describe fragrant substances
Now used to refer to the class of compounds that contain
six-membered benzene-like rings with three double bonds
14.2. Nomenclature of Benzene Derivatives
Common names are as important as IUPAC names
common property of coordination compounds is that they often occur in isomeric forms having the same empirical
formula, but with a different arrangement of atoms. Many types of isomerism exist, more so than in organic chemistry
e.g. geometrical, optical, ionisation, ligand isomerism etc. (see CH160 lecture notes). Linkage isomers arise because
some ligands can bond via one donor atom in one compound, but via a different atom of the same ligand in another
compound. Typical examples of linkage isomersism…
CHAPTER 2 (39-50; 66-69; 78-79)
Polymeric molecules- chains of chemical subunits linked end to end
Properties enable cells & organism to grow and reproduce
Cells are made of atoms
Elements – what matter is made of; hydrogen and carbon can’t be broken down by chemical means
Atom – smallest particle of element; retains its properties
At center is nucleus – positively charged; has the number of protons
Surrounded by negatively charged electrons by electrostatic attraction
and limiting reagent.
Keywords: electrophilic aromatic substitution, nitration, aldehyde, nitrating group
Electrophilic substitution happens in many of the reactions of compounds containing benzene rings - the arenes. Electrophilic Aromatic Substitution is a reaction in which the hydrogen atom of an aromatic ring is replaced as a result of an electrophilic attack on the aromatic ring (Attkins & Carey, 1990). There are steps to an electrophilic substation. First, attack of the electrophile…
atomic number of an atom is always equal
to the number of its
(1) protons, only
(2) neutrons, only
(3) protons plus neutrons
(4) protons plus electrons
8 Which is an empirical formula?
2 Which subatomic particle has no charge?
(1) alpha particle
(2) beta particle
9 Which substance can be decomposed by a
3 When the electrons of an excited atom return to
a lower energy…
CHEM 2120 Experiment 2
Column Chromatography of a Spinach Extract
Objectives Experimental Procedure
Prelab Preparation References
i. To learn the technique of column chromatography.
ii. To learn how molecular polarity determines both the solubility and the relative column migration rates (Rf) of different compounds.
iii. To determinethe relative polarity and colours of chlorophylls versus carotenoids.
Organic chemists use a variety…
Sativa (family Moraceae),
and its various preparations are known as hashish, charas, ganja, bhang, marihuana etc, depending on their mode of preparation and the country of origin. ∆9-ΤΗC belongs to a class of
compounds called Cannabinoids, a term used for the typical C21 group of compounds present
in the plant and includes their analogs and transformation products.1-3
Mainly in the last decade, many advances have been made in the cannabinoid field.4-9 At
least two types of cannabinoid receptors…