Basic Chemistry
WAIT A SECOND, ISN’T THIS BIOLOGY CLASS??
1. Why look at Chemistry?
 Here are a few reasons:
 You
may be taking Chemistry sometime in high
school, and it’s good to get a first look.
 Chemistry is necessary to understand not only
Biology, but GeoScience & Physics as well.
 The laws of chemistry explain the
structure and function of all living things.
2. How did we get here?
 The study of Chemistry has been around since
ancient times.
 In 1200 BC, ancient civilizations learned how to
extract iron ore from rock.
 In ancient Greece a man named
Democritus developed the idea of
“Atoma”
 Atoma is Greek for “indivisible,”
therefore an “atom” was thought to
be the smallest particle
 Nowadays we know there are
smaller, but he did pretty good for
400 BC!
 For
your internet searching pleasure –
neutrinos, quarks, photons, and Higgs
Bos0n
 Before the 17th Century, there
was the idea of Alchemy.
Alchemy had a lot of goals.



Create “The Philosopher’s Stone”
Transmute normal metals into gold
Create an elixir of life and live forever
 TedEd: History of Chemistry

https://ed.ted.com/lessons/solvingthe-puzzle-of-the-periodic-table-ericrosado
Obviously the Elixir of Life didn’t work out…
So what did alchemists give us?
 Ore refining
 Liquors
 Metalworking
 Distillation
 Gunpowder
 Many of the lab
 Ink & Dyes
 Paints
 Cosmetics
 Leatherworking
 Ceramics
 Glassmaking
 “Extracts”
techniques we use today!
Glass in the different states of
matter
https://www.youtube.com/
watch?v=HAPc6JH85pM
&list=TL3EV5Ko5eX2WM
72i9YrrBUx00YqsbH9Jx
 And, of course, they also gave us… Modern Chemistry!
3. Modern Chemistry & The Atom
 Everything in the world consists of matter.
 Matter: anything that has mass and occupies space.
 Matter has the following properties
 mass
: amount of matter
 volume : amount of space occupied
 density : mass / volume
 weight : the pull of gravity on mass
Matter Song:
https://www.youtube.com/watch?v=gfP4lwdehuA
Four States of Matter song (Linkin Park))
https://www.youtube.com/watch?v=vDZhUkp30tE
 The building blocks of matter are atoms!
 A single type of atom together is called an element.
 What are some elements you can think of?
 Element : pure substance made of only one kind of
atom
 Can’t be chemically broken down
 As of Nov. 2011, we’ve identified 118 elements
 Only ~20 of them are necessary for life: CHON
Carbon
Hydrogen
Oxygen
Nitrogen
Combining Atoms
 There are two ways to combine atoms:
A
compound is two or more elements.
Ex. H2O, CO2, H2SO4
 A molecule is any combination of elements
Ex. O2, H2, NaCl
 A compound is always a molecule, a molecule
isn’t always a compound!
Protons, Neutrons, Electrons
Particle
Where it’s
found
Relative Size
Charge
Proton
Nucleus of the
atom
Equal to neutron
+1
(Positive)
Neutron
Nucleus of the
atom
Equal to proton
0
(Neutral)
Electron
Outer edge of
the atom
WAY SMALLER
than proton or
neutron
-1
(Negative)
 The protons and neutrons make up most of an
atom’s mass.
 The electrons decide an atom’s charge and
reactivity.

Special electrons at the very edge of an atom’s orbit are
called valence electrons. These take part in chemical
reactions.
TedEd – Just how small is an atom?
https://www.youtube.com/watch?v=yQP4UJhNn0I
Education You Tube: Have you ever seen an atom?
https://www.youtube.com/watch?v=yqLlgIaz1L0
Pg. 14 – Video Summaries
 LEFT SIDE Write a ½ page summary of the videos you have
watched so far. Here is a list to help your memory.



How small is an atom
Have you every seen an atom
History of chemistry
 The bottom ½ will be used to summarize 2 videos on
the next slide.
The Periodic Table
 In 1869, a scientist named Dmitri Mendeleev put all the
known elements together in a table.
 He tried sorting them by their mass, but eventually realized…
 If he did it by number of protons, they all shared
characteristics.
 He even predicted elements that weren’t discovered at the
time!
TedEd: The Periodic Table created by Mendeelev
https://ed.ted.com/lessons/the-genius-of-mendeleev-s-periodic-table-louserico
Song - 3 minutes – Periodic Table song
https://www.youtube.com/watch?v=zUDDiWtFtEM
The Periodic Table
 Atomic Number

The atomic number is decided by the number of
PROTONS in the nucleus of the atom.
 Atomic Mass

The atomic mass is the number of PROTONS +
NEUTRONS
 Atomic Symbol

The symbol we use to represent the element.
Usually 1-3 letters.
Similar Properties
 Periodicity: trends that occur as you go along a row
or column of the Periodic table.

Example: The Noble gases (Neon, Argon, Krypton) are all in a
column… and don’t react with anything, no matter what.
 https://www.youtube.com/watch?v=m55kgyApYrY
Alkali metals (column 1) in water (3min)
Unusual Atoms: Ions
 Until now we’ve assumed that the number of
electrons is equal to the number of protons.
 This is not always the case. Some atoms will lose
electrons in order to be more stable. Some will pick
up stray electrons.
 What does this change?
 The charge.
 An atom that loses an electron is positive.
 An atom that gains an electron is negative.
 Both of these are called
ions.
 “Are you positive?”
Unusual Atoms: Isotope
 An atom with a different number of neutrons is
called an isotope.
 What does that change?
 The atomic mass.
 Isotopes are usually unstable and radioactive.
 Example: The atomic mass of Carbon is about 12.
 Carbon-14 is an isotope of carbon that we use to date
once living things.
 There is carbon-14 in your body right now!
Why the heck would we use anything
radioactive???
 Biological tracers
 Cancer treatment
 Radioactive dating
Radioactive Dating
 Radioactive isotopes decay over time, at an
unchanging rate.
 The amount of time it takes for half of a radioactive
substance to decay is the half-life.
Knowledge Check
 An atom of Nitrogen (Atomic Number: 7, Atomic
Mass 14) has…



7 Protons
7 Electrons
8 Neutrons
 Is it an ion, isotope, or normal atom?
 An atom of Sodium (Atomic Number: 11, Atomic
Mass 23) has…



11 Protons
10 Electrons
12 Neutrons
 Is it an ion, isotope, or normal atom?
Chemical Bonds
 Some atoms try to achieve stability by forming
chemical bonds.
 The end goal of chemical bonds is to get a full set of
valence electrons.
 Covalent Bonds
 Atoms share valence electrons
 Generally very strong bonds
Hydrogen:
Unhappy
Chlorine:
Unhappy
Hydrochloric
Acid: Happy!!
 Ionic Bonds
 A transfer of electrons from one to another
 Like magnets, opposites attract
Sodium:
Wants to lose
an electron
Chlorine:
Wants to gain
an electron
Sodium Chloride:
Everyone’s happy!
 Metallic Bonds
 Pretty much like a giant ball pit where everyone shares
electrons.
Writing Compounds & Reactions
1 .Molecular Formula =
each element represented by its symbol;
fixed; and indicated by subscript.
Examples: NaCl, H2O, H2, O2
proportions
2. Structural Formula = shows number and kind of atoms
and how atoms bond together

(lines represent bonds which are made of electrons)
 Example: H-O-H, H-C=C-H
Chemical reactions= process of breaking and/or forming
chemical bonds
Reactants go to products: 3H2 + N2
(reactants)

2NH3
(products)
Equations must be balanced because… Mass cannot
be created or destroyed
(Law of Conservation of Mass)
Important Chemical Reactions for Life
 Photosynthesis
 Creates glucose
 Cellular Respiration
 Breaks up glucose