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Transcript
Vocabulary
activity
Vocabulary
One organizer PER word (can fit 2 per page)
1. Atoms
2. Nucleus
3. Protons
4. Neutrons
5. Electrons
6. Atomic Number
7. Atomic Mass Unit
8. Covalent Bond
9. Ionic Bond
10. Elements
11. Valence Electrons
12. Ion
Quiz
Write one sentence for each of the vocabulary
words.
Use your class/homework
Particles of Matter
http://mypuzzle.org/color-link-a-pix-volume-2
Quiz
1. What are three main parts of the atom?
2. Describe the structure of the atom using
scientific and character terms.
Review
https://www.youtube.com/watch?v=gH7rfrD6
aDA
https://www.youtube.com/watch?v=O5iaw5
WNuB0
Atoms
https://www.youtube.com/watch?v=R1RMV5qhwyE
Atoms are the general term used to describe
pieces of matter
Matter is composed of atoms. Solids are made of
densely packed atoms while gases have atoms
that are spread out.
Are there pieces of matter that are smaller than
atoms? Sure there are. Super-small particles
can be found inside the pieces of atoms. These
subatomic particles include nucleons and quarks.
Nuclear chemists and physicists work together
at particle accelerators to discover the
presence of these tiny, tiny, tiny pieces of
matter. However, science is based on the atom
because it is the smallest distinct unit of
matter.
Three Easy Pieces
~ Even though many super-tiny atomic
particles exist, you only need to
remember the three basic parts of an
atom: electrons, protons, and neutrons.
~ What are electrons, protons, and
neutrons?
~ Electrons are the smallest of the three
particles that make up atoms.
~ Electrons are found in shells or orbitals
that surround the nucleus of an atom.
~ Protons and neutrons are found in the
nucleus. They group together in the
center of the atom. That's all you have
to remember. Three easy pieces!
https://www.youtube.com/watch?v=Vi91qyjuknM
~ There are almost 120 known
elements in the periodic table.
Chemists and physicists are
trying to make new ones
every day in their labs.
~ The atoms of different
elements have different
numbers of electrons,
protons, and neutrons.
~ Every element is unique and
has an atomic number. That
number tells you the number
of protons in every atom of
the element. The atomic
number is also called the
proton number.
Charges of Atoms
You can see that each part of the
atom is labeled with a "+", "-", or
a "0." Those symbols refer to the
charge of the particle.
Have you ever heard about getting
a shock from a socket, static
electricity, or lightning? Those
are all related to electric
charges. Charges are also found
in tiny particles of matter.
http://www.youtube.com/watch?v=TCUK93s1jUY
Always Moving
As you know, electrons are always
moving.
They spin very quickly around the
nucleus of an atom. As the electrons
zip around, they can move in any
direction, as long as they stay in their
shell.
Any direction you can imagine —
upwards, downwards, or sidewards —
electrons can do it.
Electrons are constantly spinning in
those atomic shells and those shells,
or orbital's, are specific distances
from the nucleus.
If you are an electron in the first shell,
you are always closer to the nucleus
than the electrons in the second shell.
Charge It
Electrons are the negatively
charged particles of atom.
Together, all of the electrons of
an atom create a negative
charge that balances the
positive charge of the protons
in the atomic nucleus.
Electrons are extremely small
compared to all of the other
parts of the atom. The mass of
an electron is almost 1,000
times smaller than the mass of
a proton
Actual atoms of Graphite
Shells and Shapes
~ Electrons are found in clouds that surround the nucleus of an atom.
~ Those clouds are specific distances away from the nucleus and are
generally organized into shells.
~ Because electrons move so quickly, it is impossible to see where they are at
a specific moment in time. After years of experimentation, scientists
discovered specific areas where electrons are likely to be found.
~ The overall shape of the shells changes depending on how many electrons
an element has.
~ The higher the atomic number, the more shells and electrons an atom will
have. The overall shell shape will also be more complex (because of the
suborbitals) as you have more electrons
Creating Bonds
~ Electrons play a major role in all chemical bonds.
~ There is one type of bonding called electrovalent bonding
(ionic), where an electron from one atom is transferred to
another atom.
~ You wind up creating two ions as one atom loses an electron
and one gains one.
~ The second type of bonding is called covalent bonding, where
electrons are actually shared between two or more atoms in a
cloud.
~ Both types of bonds have specific advantages and weaknesses
http://www.youtube.com/watch?v=QXT4OVM4vXI
Power Up
~ Electrons are very important in the
world of electronics.
~ The very small particles can stream
through wires and circuits, creating
currents of electricity.
~ The electrons move from negatively
charged parts to positively charged
ones.
~ The negatively charged pieces of any
circuit have extra electrons, while the
positively charged pieces want more
electrons. The electrons then jump
from one area to another. When the
electrons move, the current can flow
through the system.
Ions
The atomic number of an element, also
called a proton number, tells you the
number of protons or positive
particles in an atom.
A normal atom has a neutral charge with
equal numbers of positive and
negative particles. That means an
atom with a neutral charge is one
where the number of electrons is
equal to the atomic number.
Ions are atoms with extra electrons or
missing electrons.
When you are missing an electron or
two, you have a positive charge.
When you have an extra electron or
two, you have a negative charge.
What do you do if you are a sodium (Na)
atom?
You have eleven electrons — one too many
to have an entire shell filled. You need to
find another element that will take that
electron away from you. When you lose
that electron, you will you’ll have full
shells.
Whenever an atom has full shells, we say it
is "happy."
Let's look at chlorine (Cl). Chlorine has
seventeen electrons and only needs one
more to fill its third shell and be "happy."
Chlorine will take your extra sodium
electron and leave you with 10 electrons
inside of two filled shells. You are now a
happy atom too. You are also an ion and
missing one electron. That missing
electron gives you a positive charge. You
are still the element sodium, but you are
now a sodium ion (Na+). You have one less
electron than your atomic number.
Electrovalence is just another word for
something that has given up or taken
electrons and become an ion.
If you look at the periodic table, you
might notice that elements on the
left side usually become positively
charged ions (cations) and elements
on the right side get a negative
charge (anions).
That trend means that the left side has
a positive valence and the right side
has a negative valence.
Valence is a measure of how much an
atom wants to bond with other
atoms. It is also a measure of how
many electrons are excited about
bonding with other atoms.
Isotopes
Neutrons play a major role in the mass and
radioactive properties of atoms. Isotopes are
created when you change the normal number
of neutrons in an atom.
You know that neutrons are found in the nucleus of an atom. Under
normal conditions, protons and neutrons stick together in the
nucleus.
During radioactive decay, they may be knocked out of there.
Neutron numbers are able to change the mass of atoms, because
they weigh about as much as a proton and electron together. If
there are many atoms of an element that are isotopes, the
average atomic mass for that element will change.
We have spoken about carbon (C) having an average mass of 12.01.
It's not much different than you would expect from an atom with
6 protons and 6 neutrons. The number of carbon isotopes
doesn't change the atomic mass very much. As you move higher
in the periodic table, you will find elements with many more
isotopes.
https://www.youtube.com/watch?v=2HzCqnpD-zY
https://www.youtube.com/watch?v=IjZe6xSTWhM
Compound Basics
Molecule is the general term used to describe any
atoms that are connected by chemical bonds.
Every combination of atoms is a molecule.
A compound is a molecule made of atoms from
different elements. All compounds are molecules,
but not all molecules are compounds.
Hydrogen gas (H2) is a molecule, but not a
compound because it is made of only one
element. Water (H2O) can be called a molecule or
a compound because it is made of hydrogen (H)
and oxygen (O) atoms.
When we discuss phase changes in matter, we are
looking at physical changes.
Physical forces alone (unless you're inside of the
Sun or something extreme) rarely break down
compounds completely.
You can apply heat to melt an ice cube, but there
will be no change in the water molecules. You can
also place a cup of water in a container and
decrease the pressure. The water will eventually
boil, but the molecules will not change.
Chemical changes in compounds happen when
chemical bonds are created or destroyed.
Forces act on the bonds between atoms, changing
the molecular structure of a substance.
You can pour liquid acid on a solid and watch the
solid dissolve. That process is a chemical change
because molecular bonds are being created and
destroyed. Geologists pour acids on rocks to test
for certain compounds
Naming Compounds
When you have two different elements, there are
usually only two words in the compound name.
The first word is the name of the first element.
The second word tells you the second element and
how many atoms there are in the compound.
The second word usually ends in IDE. That's the
suffix. When you are working with non-metals
like oxygen (O) and chlorine (Cl), the prefix
(section at the beginning of the word) of the
second element changes based on how many
atoms there are in the compound. It's like this...
(1) Carbon + (1) Oxygen = Carbon monoxide (CO)
(1) Carbon + (2) Oxygen = Carbon dioxide (CO2)
(1) Carbon + (4) Chlorine = Carbon tetrachloride
(CCl4)