Unit 1 – What are the smallest building blocks of life?
Exam – Study Guide
A. SUB-ATOMIC PARTICLES
1. Given the mass number and atomic number list the element symbol, the number of protons,
neutrons and electrons, assuming the atom has a neutral charge overall.
A. Atomic Number = 10, Mass Number = 20
B. Atomic Number = 13, Mass Number = 27
C. Atomic Number = 38, Mass Number = 88
D. Atomic Number = 55, Mass Number = 133
E. Atomic Number = 28, Mass Number = 59
F. Atomic Number = 79, Mass Number = 197
2. If you know any two of the following seven values for a neutral atom, you can figure out the
remaining five. Use the two given numbers of figure out the missing five.
Element
Symbol
Atomic
Number
Mass
Number
Number of
Protons
Number of
Neutrons
Total Number
of Electrons
Number of
Valence
Electrons
Be 9
12 11
35 45
Na 22
3. The three most common isotopes of tin have mass numbers of 116, 118 and 120. For each
isotope, give the following information:
a. the number of protons:
b. the number of neutrons:
c. the number of electrons in the neutral atom:
d. the group number:
e. the element symbols suing superscripts and subscripts:
4. For two Isotopes of an element, they would have the same number of _______ and ______
but different numbers of _________.
A. Neutrons; Protons; Electrons
B. Electrons; Protons; Neutrons
C. Neutrons; Electrons; Protons
