02 The Atom Power Point Notes by 62I0JCj


									The Atom Power Point Notes

Fill in the notes while going through the slides.
Essential Question: what are the three subatomic particles of an atom and what characteristics does
each have?
The yellow particles shown have a positive charge and are called ____________________.
The orange particles have a neutral charge and are called _______________________.
The particles on the outer energy levels are called ___________________ and they have a negative

An atom is made up of three subatomic particles which are shown below the “atom” square.
The symbol for proton:       ______

The symbol for neutron:      ______

The symbol for electron:     ______

Protons are located in the nucleus and have a ______________________ charge. Their mass is
infinitely small, but incredibly large compared to the electron. Write the mass of a proton (1.673 x 10 24)
in standard notation.

*The relative mass of a proton is one amu, or atomic mass unit. This is the mass you need to

What is so unique about protons? They are all the same in each element, yet the number of them
identifies the element. What happens if the number of protons changes? __________________

Lithium has 3 protons therefore the atomic number of lithium is _____. The atomic number is ALWAYS
written as a whole number on the periodic table. What is the atomic number of lead (Pb) and how many
protons does it have? Atomic number = _____         Number of protons= _____

The neutron (notice the spelling, e before u) is also located in the __________________ of the atom.
What is the relative mass? ______ amu How does this compare to a proton? ___________________
The neutron just adds mass to the atom. Is the number of neutrons on the periodic table? _________
Electrons are very small but their function is extremely important in chemistry – they are responsible
for an atom’s _____________________________, or how it will react or not react with other atoms.
The electrons are located ( inside / outside ) in an area called the electron ____________________.

The electron ( IS / IS NOT ) included in the atom’s mass. Why? ___________________________
The relative mass of an electron is _________ (remember this) which is almost 2000 times smaller than
a proton or neutron!

Atomic number and Mass number
Look on the periodic table. Which element has 32 protons? ______symbol ________________name
Which element has 14 protons? _____ symbol       ____________________ name

The ___________________ _____________________ is the number of protons plus the number of
neutrons in an atom. Why? _________________________________________________________

If you know the mass number of an element and its name you can find it on the periodic table and
calculate how many neutrons it has by subtracting. Mass # - atomic # = neutrons #

Write the formula for finding the neutrons: ____________________________________________
Three types of Atoms

Many atoms of the same type are called an ________________________. An atom that has a charge
is no longer neutral and is called an ____________________. All individual atoms are an isotope of its
element depending on the number of neutrons it has.

An atom is neutral, meaning it has the same number of positive charges ( protons / electrons ) as
negative charges ( protons / electrons ).

What is the particle called when the number of protons and electrons in an atom do not match?


Atoms with the ______________ number of protons but different numbers of neutrons are called
____________________________. Most elements have isotopes with the exception of a few. The
larger the atomic number the ( greater / smaller ) the difference in the numbers of protons and
neutrons. Isotopes of elements having many neutrons “rich” in comparison to protons are unstable.
Isotopic Notation

                                              The isotopic name of an element is always paired with its
                                              ( mass / atomic ) number. Ex: silicon-28
                                              Do not use the atomic number! That would be redundant.
                                              The shorthand notation is written with the mass number
                                              on top and the atomic number on the bottom and the
                                              symbol of the element to the right. It is then easy to
                                              find the number of neutrons. Can you explain how?

                                              Notice the differences between the isotopic notation and
the isotopic name. You must learn how to do this! It just takes practice.

These are three known isotopes of carbon; carbon-12, carbon-13 and carbon-14. Fill in the chart to see
how they differ.

Isotopes are atoms of the same element with the same number of _____________________ but with
different numbers of _______________________________.

Complete the blanks for the three isotopes on the chart.

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