Name: _________________________
Class Period: _____
Mini-Lab Investigation:
Naming Atoms, Ions, and Isotopes
Purpose: The purpose of this investigation is to practice identifying atoms,
ions, and isotopes by the relative numbers of protons, neutrons, and
electrons present in a particle.
Introduction:
Atoms are composed of three different particles – protons (p+), neutrons (n0), and electrons
(e-). The identity of the atom is determined by its number of protons. For example, an atom with 1
proton in its nucleus must be hydrogen (atomic number = 1). Similarly, an atom with 10 protons in its
nucleus must be neon (atomic number = 10). Every atom of a particular element contains the same
number of protons.
Atoms can gain or lose electrons to form ions. A neutral atom will contain the same number of
protons (+ charges) and electrons (- charges). When an atom loses electrons, it forms a cation – a
positively charged ion. When an atom gains electrons, it forms an anion – a negatively charged ion.
Atoms of the same element can have different numbers of neutrons. These are called isotopes and
they have different mass numbers. To determine the mass of an atom or isotope, simply add up the
number of protons and neutrons present in the nucleus of the atom.
6
element symbol
atomic number
C
carbon
mass number
element name
12.011
# of protons = atomic number (unique to each element)
# of neutrons = mass number - # of protons
# of electrons = # of protons (if atom is neutral)
Pre-Lab Questions:
1. Write the element symbol for the following atoms:
a) 6 protons, 6 neutrons, 6 electrons
_____________
b) 18 protons, 20 neutrons, 18 electrons
_____________
c) 3 protons, 4 neutrons, 3 electrons
_____________
2. Write the isotope name for the following atoms:
a) 8 protons, 8 neutrons, 8 electrons
_____________
b) 15 protons, 16 neutrons, 15 electrons
_____________
c) 30 protons, 36 neutrons, 30 electrons
_____________
(continued)
3. Write the symbol for the following ions:
a) 3 protons, 4 neutrons, 2 electrons
______________
b) 12 protons, 12 neutrons, 10 electrons
______________
c) 16 protons, 16 neutrons, 18 electrons
______________
Procedure:
1. At each lab station is a bag labeled A-R. Each bag contains varying amounts of protons (white
paper clips), neutrons (red paper clips), and electrons (black paper clips).
2. For each bag, record the number of protons, neutrons, and electrons in the Data Table.
3. Using these values and the periodic table, complete the remaining columns and determine the
atom/ion symbol.
Data Table:
Bag
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
# of protons
# of neutrons
# of electrons
Element
Name
Mass Number
Symbol for
Atom or Ion