Download What is an atom?

6th Grade Science
Matter
5.4 The student will investigate and understand that matter is anything that
has mass, takes up space, and occurs as a solid, liquid, or gas. Key
concepts include
atoms, elements, molecules, and compounds
6.4 The student will investigate and understand that all matter is made up of
atoms. Key concepts include
atoms are made up of electrons, protons, and neutrons;
atoms of any element are alike but are different from atoms of other elements;
elements may be represented by chemical symbols;
two or more atoms may be chemically combined;
compounds may be represented by chemical formulas;
chemical equations can be used to model chemical changes; and
a limited number of elements comprise the largest portion of the solid Earth,
living matter, the oceans, and the atmosphere.
Matter (anything you can
touch) is composed of atoms.
Matter comes in 5 forms but the
most common are solids,
liquids and gases.
Matter can be described and
identified by physical and
chemical properties.
The most common are solids,
liquids and gases.
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There are 2 main locations in an atom:
nucleus (the center with most of the mass of the atom)
electron cloud (surrounds the nucleus)
There are 3 subatomic particles in an atom:
subatomic means smaller (than the atom itself)
3 particles = protons, neutrons and electrons
the numbers of these particles make atoms
different from one another.
Atoms are the smallest particle of an element that
retains its identity in a chemical reaction.
Not very big. You’d need
special microscopes to
see them.
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ATOMS ARE MADE UP OF
SUBATOMIC PARTICLES
Atoms are made of even smaller particles called
subatomic particles.
Electrons
Protons
Neutrons
Negatively charged subatomic particles. They are
1,000 times smaller than a proton.
Electrons are found in clouds that surround the
nucleus but because they move so quickly, it is
impossible to see where they are at a specific
moment in time.
In the world of electronics these very tiny
particles stream through wires and circuits
creating currents of electricity that power
computers, lights, radios and other appliances.
Protons are positively
charged subatomic
particles.
Inside the proton are
even smaller
particles called
quarks. Jefferson
Lab in Virginia was
built to study these
quarks in 1968.
Neutrons are subatomic particles with no charge.
Their mass is nearly equal to the proton.
Neutrons are related to the radioactive properties
of atoms.
The nucleus of the atom is made of protons and
neutrons.
The electrons are in constant motion around the
nucleus.
Democritus
Was a greek
philosopher who
believed that all
matter was made
up of a smaller
particle called the
atom.
John Dalton (17661844), a scientist,
studied the ratios in
which elements
combine and the
result was Dalton’s
atomic theory.
John Dalton was a scientist
who postulated that
All elements are
composed of
tiny particles
called atoms.
Atoms of the same
element are
identical.
Atoms of different
elements are
different
Dalton’s Theory states:
All elements are
composed of tiny
particles called atoms.
Atoms of the same
element are identical.
Atoms of different
elements are different.
Dalton’s Theory states:
Atoms of different
elements can
physically mix
together or
chemically
combine in simple
whole number
ratios to form
compounds.
Dalton’s Theory states:
Chemical reactions
occur when atoms
are separated,
joined, or
rearranged. Atoms
of one element are
never changed.
THOMSON MODEL THE FRUITCAKE 1897
HE DISCOVERED THE
ELECTRON. HE WAS
WRONG TO BELIEVE
THAT ELECTRONS WERE
SCATTERED
THROUGHOUT THE
ATOM LIKE PLUMS IN A
PUDDING.
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Atoms are made of
mostly space.
The center of the atom
has a positive nucleus.
Rutherford changed how people
thought about atoms when he shot
rays through extremely thin gold
foil. He concluded that most the of
alpha particles pass through an atom
because it is mostly empty space.
A few particles were deflected because
of a positive charge from the nucleus
that pushed them.
BELIEVED ELECTRONS
MOVE IN THEIR OWN
PATHS ON A CERTAIN
ENERGY LEVEL AWAY
FROM THE NUCLEUS.
ELECTRONS CAN JUMP
FROM ONE ENERGY
LEVEL TO ANOTHER
LIKE PLANETS ORBIT
THE SUN….
PRESENT ATOMIC
MODEL
A CLOUD-LIKE REGION
WHERE THE ELECTRON
IS LIKELY TO BE
FOUND. IT CAN NOT
SAY WITH ANY
CERTAINTY, WHERE THE
ELECTRON ACTUALLY IS
AT ANY POINT IN TIME,
YET CAN DESCRIBE
WHERE IT OUGHT TO BE.
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Werner Heisenberg was really the person that
determined that the only way to describe the
location of electrons is as a probability
distribution, and this led to the idea of an
"electron cloud" where you can only talk about
the relative probability of find an electron in a
certain volume.
The atomic number of an element is the number
of protons in the nucleus .
Hydrogen (H) has 1 proton so its atomic number is 1
All Oxygen atoms (O) have 8 protons, so the atomic
number of Oxygen is 8.
The mass of an atom is the total number of
protons and neutrons in an atom. Electrons are
so small they don’t count towards mass.
Carbon (C) has 6 protons and 6 neutrons so its
mass number is12.
Helium (He) has 2
protons and 2
neutrons so its mass
number is 4.
The number of
neutrons = Mass
number - Atomic
number
OR
Atomic number +
number of neutrons
= mass
Elements are the building blocks of
all matter.
A limited number of basic elements
make up our universe. Up to this
point in time we have
discovered/created over 100.
Try this quiz from the Jefferson lab
http://education.jlab.org/reading/p
roperties_and_changes.html
If everything is made of atoms, why are some
elements gases, others solid and some liquid?
Atoms differ from each other by the number of
protons, neutrons and electrons. This in turn
causes each element to be different.
The number of protons is the final determining
factor.
Atoms prefer to have full shells (parts of the
electron cloud.) Its rather like needing 5 people
for a basketball team or 11 to play football.
Atoms with too many electrons (one or two extra)
give them up while those close to having a full
shell look for atoms who will give them one or
two.
This is called ionic bonding
Sometimes atoms share
electrons – this is called
covalent bonding. This
would be like two coaches
sharing an athlete.
Sometimes the athlete would
play basketball, sometimes
play football.
Electrons move so quickly, it is
almost like they can play
football and basketball at the
same time.
Elements are organized on
the periodic table
according to their
structure.
Carbon, hydrogen, oxygen
and nitrogen are the
most common elements
in our world.
A table to hold
punctuation like
periods and commas?
A place where atoms
periodically have
picnics?
An organized chart of
the elements?
An organized chart of
the elements
Carbon, hydrogen, oxygen
and nitrogen are the
most common elements
in our world.
Ionic bonding is when atoms
with too many electrons
(one or two extra) give
them up while those close
to having a full shell look
for atoms who will give
them one or two.
Jefferson Lab
http://education.jlab.org/atomtour/listofparticle
s.html
Chem4kids
http://www.chem4kids.com/files/atom_intro.ht
ml
Quia matching game
http://www.quia.com/mc/1662210.html
Quia rags to riches game (like Millionaire)
http://www.quia.com/rr/143370.html
Another rags to riches
http://www.quia.com/rr/327025.html
Atomic structure jeopardy
http://www.quia.com/cb/147081.html
Atoms and molecules cloze activity
http://www.quia.com/cz/91566.html
Quia quiz on Atom and Periodic Table Review
http://www.quia.com/quiz/890298.html
All about atoms
http://www.quia.com/quiz/253521.html
Chem4kids structure of the atom
http://www.chem4kids.com/extras/quiz_atoms
truct/index.html