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Name: ________________________________________ Homeroom: ____________
Chapter 12 – Atoms and Elements
Essential Question: What is Matter Composed of?
An element is a substance made up of only one kind of atom. Examples of
elements are __________________________________________________________.
The Atom
An atom is the smallest unit of an _________________ that can still be identified
as that element. After studying atoms scientist believe that a single atom is made up of
even ________________ pieces known as subatomic particles. Each atom also has
a center or ___________________.
There are three types of subatomic particles:
Proton - ___________________ electric charge. The nucleus of an atom contains at
least _________ proton.
Neutron - ______________ electric charge and the same mass as a _____________.
Most atoms _________________ contains one or more neutrons.
Electron - _______________ electric charge. ____________ the nucleus at great
speeds.
Even though elements contain the same subatomic ______________ they are
different because they contain a ________________ number of subatomic particles.
The most important subatomic particle is the number of _______________. The
number of protons in an ____________ is its atomic number. Each element has its
own ____________ number meaning it contains a different number of _____________.
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Isotopes
All atoms of one element have the same number of _________________, but do
not all have the same mass. Some are heavier because they have a different number of
______________________ in their nuclei.
Atoms that have the _____________ number of protons but ______________
numbers of neutrons are called isotopes. An isotope can be identified by using a value
called an __________________________________. Atomic mass is the __________ of
the number of neutrons and the number of protons in the _____________________.
Essential Question: What Are Elements and Compounds?
Elements
An element is a substance that contains only __________ kind of atom. All
atoms of an element have the same number of __________________________, also
their atomic number.
At this time we know more than _________ elements, but only 90 of these occur
in nature. Some familiar natural elements are : ________________________________
______________________________________________________________________
Periodic Table
The periodic table is to organize the ________________ by their atomic number.
Each element has a specific ________________ in the table. The box where the
element can be found contains the elements ______________, __________________,
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and ________________. The element’s symbol is one or more __________________
that stands for the element. Some are easy to remember such as _____ for hydrogen,
while others are not such as ______ for gold.
One of the most useful tools of the _____________ table is that it arranges the
columns (up and down) of elements into a family. Each column or family of elements
has similar _________________.
How Compounds Are Formed
A compound is a substance made of atoms of two or more ________________
that are chemically combined. The chemical formula for a compound shows the
_________________ that are in the compound. The chemical formula also compares
the number of __________________ of the different elements within the compound.
Compounds do not have the same ____________________ as the elements that
form them. Water is a familiar compound. Water is 2 ____________________ atoms
combined with 1 ___________________ atom. Water’s chemical formula is H 2O .
A compound holds together because atoms __________________ to one
another.
Compounds in Nature and in Industry
Elements are not often found in their pure form. Generally our world is made up
of __________________________. Removing an element from a compound is not an
____________ process.
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Essential Question: What Are the States of Matter?
States of Matter
Matter has 3 different states:
Solid: a definite _______________ and a definite volume. Solids have their own
shape.
Liquid: a definite ___________________ but NO definite shape. A liquid takes the
shape of the container that holds it.
Gas: NO definite _______________ or NO definite ________________. Gas expands
to fill whatever space is available. (think of a balloon)
Matter can exists in three different states solid, liquid, or gas because of the
different amounts of the _____________________, or motion of their atoms or
molecules.
Changes of State
The atoms and molecules of all elements and compounds can exist in each state
of matter: ______________, ________________, or ___________. Each changes
state at certain temperature depending on the substance. Adding or removing
____________ cause changes in state. The increase of decrease of _______________
on a substance can also cause changes in states of matter.
Melting Point: temperature at which a substance changes from a solid to a
_______________.
Boiling Point: temperature at which a substance changes from a liquid to a _______.
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When a gas is cooled below the boiling point it becomes a ______________.
When this liquid is cooled below the melting point it becomes a ______________.
A substance that can change from a solid directly to a gas without first becoming
a liquid goes through a process called _____________________.
Plasma
Plasma is a mixture made up of ______________ atoms, _______________
atoms, and _________________. Plasma is the fourth state of matter. Is rare on
Earth, but makes up ____% of all matter in the universe. _______________, interstellar
clouds, and comets are mostly plasma.