Download Intro to atoms and the periodic table

Atoms and the Periodic
Table
Chapter 17
Objectives
At the end of this lesson, you should be
able to:
Describe and define atoms and their
subatomic particles
Describe the relationship between
atoms and elements
Describe how atoms are held together
17.1-Elements contain a single
kind of atom
Atoms make up all of the matter around
you.
To date, there about 120 known distinct
atoms
about 90 are found in nature
17.1-Elements contain a single
kind of atom
Element - any material made of only 1
type of atom (ex. gold, nitrogen)
All elements are listed in a chart called
the periodic table
Each element has its own atomic symbol
What is an element?
A.
A material containing 1 or more atoms.
B.
A material made of only 1 type of atom.
C.
A material made of 1 or more atoms
chemically bonded together.
17.1-Elements contain a single
kind of atom
Atoms - very, very old
Formed @ beginning of the universe
Recycled and redistributed over and
over
17.1-Elements contain a single
kind of atom
Atoms - very, very small
Can’t be seen w/ visible light
Smaller than wavelengths of visible light
17.1-Elements contain a single
kind of atom
Atoms - made of subatomic particles - electrons,
protons, and neutrons
Atoms only differ in # of these particles
p’s and n’s-bound together to form the atomic
nucleus
e’s - surround nucleus in an electron shell or
electron orbital
Can’t pinpoint location of e’s - just know about
where they are in shells/orbitals
17.2 - Atoms are mostly empty
space
e’s move around the nucleus in an atom,
but are widely separated from the
nucleus
∴, atoms are mostly empty space.
Which two subatomic particles can be found
in the atomic nucleus?
A.
Proton and electron
B.
Electron and Neutron
C.
Neutron and proton
17.2 - Atoms are mostly empty
space
Atoms don’t pass through each other
because of electrical repulsion
Like charges repel - they move away
from each other
So, atoms can only get so close before
they start repelling each other
17.2 - Atoms are mostly empty
space
How are atoms held together?
Electrical forces - forces of attraction or repulsion
Protons have a + charge; Electrons have a charge
Opposite charges attract each other The positively charged nucleus (p’s and
n’s) is attracted to the negatively charged
electrons, thus holding the atom together.
Atoms are held together by the electrical
attraction between
A.
The negatively charged nucleus and the
positively charged electrons.
B.
The negatively charged electrons and the
neutrally charged nucleus.
C.
The negatively charged electrons and the
positively charged nucleus.