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Vocabulary/Concept
1. What are elements?
2. What are atoms?
3. What are molecules?
4. Who was the first person to suggest or
identity the atom?
5. What are the four parts of an atom?
6. What is a nucleus?
7. What's the difference between protons and
neutrons?
8. What makes up the rest of an atom?
9. How many electrons are in each energy
shell?
10. What are electrons?
11 . What do electrons and protons have in
common?
12. What is the purpose of the periodic table?
13. How is the Periodic Table arranged?
14. What do the periods represent?
Definitions/Description/Examples
Elements are substances that cannot be separated into simpler
substances. Elements are made up of atoms,
Atoms are the basic unit of matter that makes up everything
around us. It's the "stuff".
Molecules are a combination of two or more atoms. Ex: A
water molecule includes two hydrogen atoms and one oxygen
atom.
Democritus — Greek philosopher who first used the word
atom to describe the smallest thing found in the universe and
believed that if you continued breaking down an object into
smaller and smaller pieces, you would eventually end up with
an atom. The word atom means "cannot be destroyed".
Protons, Neutrons, and Electrons
The nucleus is the center part of an atom, which contains
protons and neutrons. The nucleus takes up only a very small
fraction of an atom's space, but almost 100 percent of its mass
(comes from the protons and neutrons-roughly the same size
and weight)
Protons=positive charge Neutrons=no charge
The rest of an atom is mostly empty space called energy clouds
where electrons are found. Within the energy cloud, electrons
move in energy levels called shells-Electrons in the outermost
energy shell interact and bond with other atoms.
Starting from the nucleus, the shells can hold 2, 8, 18, and then
32 electrons
Electrons are smaller than you can imagine and have almost no
mass. They weigh about 2000 times less than protons and
neutrons and have a negative charge.
Usually an atom has the same number of electrons and protons,
so their charges balance each other. This makes the atom
neutral. Ex: The element Nitrogen has seven protons in its
nucleus. This means that it has seven electrons. The atomic
number on the Periodic Table is also seven.
Properties of elements can be identified or predicted based on
its location on the periodic table.
7 horizontal rows called periods and 18 vertical columns called
groups or families.
AH of the elements in a period have the same number of
energy shells. Every element in the top row (the first period)
has one shell for tls electrons. All of (he demenis in the second
row (the second period) have two shells for their electrons. It
goes down the periodic table like that. At this time, the
maximum number of electron shells or electron shells for any
element is seven.
15, What do the groups or families represent?
The elements in a group have the same number of electrons in
their outer shell. Every element in the first column (group one)
has one electron in its outer shell. Every element on the second
column (group two) has two electrons in the outer shell. As
you keep counting the columns, you'll know how many
electrons are in the outer shell, but there are some exceptions.
16. What are some exceptions?
Hydrogen and helium are special elements. Hydrogen can
have the talents and electrons of two groups, one and seven.
To scientists, hydrogen is sometimes missing an electron, and
sometimes it has an extra. Helium is also different from all of
the other elements. It can only have two electrons in its outer
shell. Even though it only has two, it is still grouped with
elements that have eight.
17. What is an atom's atomic number?
The atomic number is equal to the number of electrons in an
atom. If the atom is neutral, the atomic number is also equal to
the number of electrons.
The chemical symbol is an abbreviation of an clement.
1 8. What is the chemical symbol of an
element?
19. What is the atomic mass?
20. What is the Lewis Dot Diagram?
The atomic mass is the amount of "stuff that makes up an
atom. The atomic mass is the total mass of an atom's protons,
neutrons, and electrons.
The Lewis Dot Diagram helps to show the number of valence
electrons an atom can hold. Valence electrons are the most
important electrons in an atom, which are found in the outer
energy level.