Slides in this set
What is this unit about?
The periodic table is an extremely important. It helps us
understand the mass of information about of all of the
elements. This unit is
all about the chemical
reactions between the
Describe the structure of an atom
An atom is a basic unit of matter consisting of a central
nucleus surrounded by negatively charged electrons. The
atomic nucleus contains a mix of positively charged protons
and electrically neutral neutrons (except in the case of
hydrogen, which is the only stable nuclide with no neutron).
The electrons of an atom are bound to the nucleus by the
electromagnetic force. Similarly, a group of atoms can
remain bound to each other, forming a molecule. An atom
containing an equal number of protons and electrons is
electrically neutral, or else it is positively or negatively
charged and is an ion. An atom is classified according to the
number of protons and neutrons in its nucleus; the number
of protons determines the chemical element, and the
number of neutrons determines the isotope of the element.
What do the atomic mass and number of an
atom tell us?
The atomic mass tells us the total amount of atoms in the
element i.e. The total mass of protons, neutrons and
The atomic number of an atom tells us the amount of
protons inside of the nucleus. In an atom of neutral
charge, the number of electrons and the atomic
number, are the same, which in all elements is true.