Download The Atom

The Atom
What is an atom?
Atom – the basic particle from which all elements are made
What is inside an atom?
An atom is made up of 3 subatomic particles.. an atom consists of a
nucleus surrounded by an electron cloud
Proton – a subatomic particle with a positive charge and a
mass of 1amu; found in the nucleus of an atom
Neutron – a subatomic particle with no electrical charge (a
neutral charge) and a mass of 1amu; found in the nucleus of
an atom
Electron – a subatomic particle with a negative charge and
has very little mass; found in the electron cloud, which is
located outside of the nucleus
Out of the three subatomic particles, which particle has the
smallest mass?
The electron has the smallest mass (less than 1amu)
Which one of the subatomic particles has a positive charge?
The proton has a positive charge (proton = +)
Atom and Elements
An element can be identified by the number of protons in the nucleus
of its atom – an element can NEVER, EVER lose a proton!
Element – a pure substance that cannot be broken down into
other substances by chemical or physical means – hydrogen (H)
or Sodium (Na) are examples of elements
Atomic Number – the number of protons an element has in
its nucleus – an element can be identified by the number of protons
in the nucleus of its atoms
Atomic Mass – is the number of protons and the number of
neutrons in the nucleus of an atom – most of the atomic weight of
an atom comes from the protons and neutrons, which are located in
the nucleus of an atom
Although all atoms of an element have the same number of
proton, their number of neutrons can vary…
What is a neutrons charge, and where is it located?
Isotope – atoms with the same number of protons and a
different number of neutrons
Ex: Carbon-12 (6 protons and 6 neutrons)
Carbon-13 (6 protons and 7 neutrons)
Carbon-14 (6 protons and 8 neutrons)
*Although these carbon atoms have different mass numbers, all
carbon atoms react the same way chemically