Name _________________________________
Date ____________
Period _________
Atoms, Elements, Compounds, and Mixtures -- Notes Pages for
PowerPoint Presentation
Slide 1: Structure of the Atom
 Atoms are the ________________ into which matter can be divided and still maintain its
characteristics.
 Atoms are the __________________ of the universe. There are ___ different kinds of atoms
that occur naturally, although more are man-made.
 These building blocks can be ________________________ to create all of the different kinds
of matter we can observe.
 All atoms share the _____________________. Over the years, scientists have designed
________________ ____________ for this structure.
 Each one was the best model at the time, but as _________________________________, the
models were revised to fit it.
 Scientists will probably ____________ the current model as more evidence becomes
available.
Slide 2: Early Atomic Models
 The Greek scientist _______________ was the first person to say that all matter is made of
atoms, but he also said that atoms are ____________________.
 In the early 1800’s, the English scientist ______________________ developed his
____________________________________. It said four things:
(1) _____________________________________________.
(2) _____________________________________________.
(3) ___________________________________________________________.
(4) ______________________________________________________________.
 In the late 1800’s, ___________________ discovered that atoms were made of smaller
particles. He discovered the _____________ and devised the “____________________”
model of the atom.
Slide 3: Recent Atomic Models
 In the early 1900’s, scientists discovered the positively-charged ____________. In 1911,
__________________ discovered the ______________ of the atom, where protons are
located. Atoms are mostly ____________________________.
 Niels Bohr changed Rutherford’s model in ___________. Bohr said that electrons move
around the nucleus in __________________________. Electrons can move from one energy
level to another. Bohr’s model has been called the “________________” model of the atom.
 The current model of atomic structure is called the “________________” model. Electrons
move within an energy level ________________________________, not a fixed orbit.
__________________ bond with protons in the nucleus.
Slide 4: Atomic Number and Mass Number
 All atoms of an element have the _________ number of protons, and different elements have
______________ numbers of protons in their atoms.
 The atomic number of an atom is the number of _____________ it has. If the atom is
neutral, the atomic number is also the number of ________________.
 Atoms of the same element may have different numbers of _____________. Atoms with
extra or missing neutrons are called _________________.
 An atom’s mass number is the number of ______________ plus ______________.
 Different isotopes of an element have different ____________ numbers.
Atomic number of this neutral atom = 6.
This means that it has 6 ___________ and 6
______________.
Mass number of this neutral atom is 14. This
is the sum of the _____________ plus
______________. Since there are 6 protons,
there must be 14 - 6 = ____ neutrons.
Slide 5: Elements
 An element is matter that is made of only ________ kind of atom. All of the atoms of an
element are _____________. There are ________ naturally occurring elements.
 Elements can be identified by their _____________________. Some properties are _______,
_____________, _______________, _________________, __________________, ability to
__________________ in water, and ability to conduct _________or ___________________.
 At room temperature, most elements are _______________, although a few are
________________ and some are ________________.
 Chemical ________________ are abbreviations for the names of elements. You can also use
a chemical symbol to represent one ___________ of an element.
 Chemical symbols are the same all over the world, no matter what language is spoken. The
first letter is _________ capitalized, and if there is a second letter it is _________ capitalized.
Slide 6: Compounds
 The atoms of most elements are very _____________. They __________________ join
together with atoms of other elements to form _____________________.
 The properties of compounds are ________________________than the properties of the
elements that make the compound.
 When elements join to make compounds, they _________________ join in the same
proportion. H2O is water, not HO or H3O !
 Compounds are separated into __________ groups, depending on how their atoms are joined:
(1) Molecular compounds are made of atoms that ____________ electrons.
(2) Ionic compounds are made of atoms that ________ or ___________ electrons.
 Chemical ________________ represent compounds. They show the _________ and
______________ of atoms in the compound.
H2O
H is symbol for ____________________
O is symbol for _____________________
Subscript 2 means that there are ___ Hydrogen atoms
No subscript means ____ Oxygen atom
Water molecule
NH3
N is symbol for _____________________
H is symbol for ___________________
No subscript means ____ Nitrogen atom
Subscript 3 means there are 3 ________________
atoms
Ammonia
Molecule
Slide 7: Mixtures
 Mixtures are made when there are at least ______________ different kinds of atoms that are
in the same place but are ______ chemically combined.
 A mixture can be made with __________ proportion of ingredients, but a compound must be
made in only ________ certain way.
 Components of a mixture _____________ their own properties, but those of a
___________________ do not.
 Components of a mixture are not ____________________ combined, so they can be
separated by _________________ means.
Slide 8: Types of Mixtures
 A homogeneous mixture is __________________ throughout. All parts of the mixture have
the ___________ proportion of ingredients.
 A heterogeneous mixture is ________________________ in different parts. Different
regions of this kind of mixture have ____________________ proportions of the ingredients.
 An ______________ is a homogeneous mixture of metals.
 All ________________________ are homogeneous mixtures.
Homogeneous mixtures
Heterogeneous mixtures
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