Download Getting to know and love our atoms, more and more each day

Chapter 2.1
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H
hydrogen
______________________ = ____________________
______________________
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The elements
1. The elements in Mendeleev’s periodic table are arranged in rows (left to right) called ___________.
These rows are arranged in order of __________________ atomic mass.
2. The elements are also arranged into columns (up and down) called _____________ or
______________. The elements within each column have similar _______________
________________, for example similar boiling points and/or melting points.
3. Elements are any substance that ____________ be broken down into simpler substances. A pure
substance that consists entirely of one type of atom.
4.
Humans are mostly what four elements (96% of your body)? ______, _____, _____, ______.
5.
What are the six elements found in every living thing?____, ____, ____, _____, ____, _____
6.
What are the other elements that make up your body called that are found in
small amounts like copper and iodine? _____________________________
Sub-particles of atoms (electrons, protons, and neutrons)
1. An ______________ is the smallest particle of an element that has the
characteristics of that element and forms the basic building blocks of all matter.
2. In other words, atoms are made up of ___________,_______________, and
_______________.
3. The Greek word atomos means “unable to be cut”.
4.
Which 2 particles make up the nucleus of an atom? ______________, _________________
5.
What are the charges on each of the 3 parts of an atom?
Electron (e-)____
6.
Proton (p)_____
Neutron (n)________
How is an atom held together?______________________________________________
Atomic Number
1. The ________________ ________________ tells how many ____________ an element has.
2. In a NEUTRAL ATOM:
Protons equal the number of ___________________.
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Determining number of protons, neutrons, AND electrons
1. To determine the number of ________________________:
Atomic mass = (# of protons) + (# of neutrons)
Ex: Hydrogen has how many p ________
Hint: use algebra to solve for the missing value!
n___________ and e-____________
Using the periodic table that has been provided to you answer the following three questions:
Q: How many protons, neutrons and electrons are in He? p =_____, n = _____, e = _____.
Q: How many protons, neutrons, and electrons are in N? p =_____, n= _____, e = _____.
Q: How many protons, neutrons, and electrons are in Be? p =_____, n = _____, e = _____.
Important: The periodic table is reflecting neutral atoms. We will discuss atoms that are not
neutral later (isotopes and ions)!
What kind of change would affect the mass of an atom?
1. A change in the number of __________ would change its atomic number, as well as all of its
chemical properties. It would be a _______________________ element!
PROTON COUNT WILL NOT CHANGE!
2. A change in the number of __________would NOT change its chemical properties, but will affect
the mass. An atom with a different number of neutrons is called an ______________________.
3. A change in the number of __________would change its chemical properties, but it will NOT affect
the mass. An atom with a different number of electrons is called an ____________________.
Bohr Models / Electron Cloud Models
1. Electrons float around the nucleus in: Orbitals / Shells / Electron Clouds / Energy Levels
2.
How many electrons are in the first orbital (inner shell) of:
C (atomic no. = 6)
_____
S (atomic no. = 16) _____
N (atomic no. = 7)
_____
P (atomic no. = 15 ) _____
3. 1st Orbital holds how many electrons?: ________________.
4. How many electrons are in the second orbital of:
C (atomic no. = 6)
_____
S (atomic no. = 16) _____
N (atomic no. = 7)
_____
P (atomic no. = 15 ) _____
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5. The Bohr model rules are as follows:
1st orbital : holds at most _______ electrons
2nd and 3rd orbital: holds at most _______ electrons
4th and beyond orbital: holds at most ________ electrons
6. How to draw a Bohr model
1) draw a nucleus (write inside the number of protons and neutrons)
2) draw the orbitals filling in the correct number of electrons (until you run out of electrons)
Example: Draw the Bohr model of Lithium
7. Activity: Draw and label a one dimensional “Bohr” model of H and Na below. Need Periodic table.
8.
Why is the Bohr model inaccurate/ outdated?
________________________________________________________________________
9.
Look at the electron configuration of these first column elements. Explain the trend(s) you see:
________________________________________________________________________________
________________________________________________________________________________
10. What are electrons in the outermost orbital called? ______________________________________
11. Look at the electron configuration of the second column elements (Be, Mg, Ca), what trend(s) do
you see? You may want to try sketching one or two of them out.
_________________________________________________________________________________
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12. The numbers above the “A” columns = the number of ___________ electrons. These are the electrons that
react with other elements.
For now we will ignore the “B” columns (transition metals) because they react differently than the 8 main
group elements.
1A
8A
2A
3A 4A 5A 6A 7A
[----(these are the transition metals)------]
How many valence electrons do the following elements have?
Mg ____________
O ____________
Cl_____________
All atoms want out of life is…_____________________________________________________
1.
Name some atoms that naturally have their outermost shell filled.
(
) ____________
(
) ____________
(
) ____________
(
) ____________
These gases are commonly referred to as the _________________ ________________
2.
So what can atoms do to be more like the noble gases / more stable in terms of their electrons?
_________________________, _________________________, _________________________
3. Examples: what do the following need to lose (or gain) to be “stable”?
Na _________ Be _________ B__________ C__________ N __________ O__________ F_________
Chemical equations
1. The process of showing how the atoms bond/ come together is represented in a chemical
___________________. For example, let’s form 2 water molecules.
2H2 + O2  2H2O
What are the substances to the left of the arrow called? ________________________
What are the substances to the right of the arrow called? _______________________
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2.2 Notes
Heterogeneous Mixtures and Solutions (aka Homogeneous Mixtures)
1. Heterogeneous Mixtures are a combination of ______________________ that when put together the
individual components keep their own ______________________.
Give an example of a mixture: _________________________________________
2. Solutions (aka homogeneous mixtures) are a combination of substances that when put together they are
distributed _____________________. The substance doing the dissolving is called the
_________________________ and the substance being dissolved is the _________________________.
This is easy to remember because _________________ is often referred to as the
__________________________ solvent.
Give an example of a solution: __________________________________________
What part of that is the solute? _________________ the solvent? ______________
pH (how acidic a solution is)
1. The pH scale tells the amount of ______________ions in
a solution.
2. It is a measure of how _________________ or
__________________/ ___________________ a
solution is.
3. The pH scale ranges from ________ to _________.
4. Substances less than 7 are __________________,
substances greater than 7 are _______________, substances
at 7 are ___________________.
5. The true definition of an acid is any substance that forms __________________ in water. The true
definition of a base is any substance that forms __________________ in water.
6. An example of a neutral solution is: _____________________
7. An example of an acidic solution is: _____________________
8. An example of a basic solution is: ______________________
9. Acid + Base = ___________________________
10. How does antacid with a pH of 10 soothe an upset stomach?
___________________________________________________
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11. A buffer solution is an aqueous solution consisting of a mixture of a weak ___________ and its conjugate
___________ (or vice versa). The ___________ changes very little and is used as a means of keeping pH at
a nearly _________________ value.
12. An example of a buffer solution is ________________ because many life forms only thrive in a relatively
________________ pH range.
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