Download Academic Chemistry Chapter 3 Review Activity

Mr. Demascal
Chemistry
Name____________________________________
Date ________________________Period_______
Chapter 3, Part 2 Review Packet
Define what an ATOM is:
An atom is the smallest particle of an element that still retains the properties of that element.
List the three subatomic particles, their symbols, charges and explain where they are located at in the structure
of the atom.
Proton, p+1, +1 charge, located in the nucleus
Neutron, n0, no charge, located in the nucleus
Electron, e-1, -1 charge, located in energy levels surrounding the nucleus
What is an isotope and how do these atoms differ from each other?
“Isotopes” refer to atoms of the same element that have different mass values. This is a result of having a
different number of neutrons in the nucleus.
How are Cl – 35 and Cl – 37 similar and different?
Similar – both contain 17 protons and 17 electrons
Different – Cl-35 contains 18 neutrons while Cl-37 contains 20 neutrons.
Using the information provided below and your periodic table, Determine the number of protons, neutrons and
electrons in atoms of the following elements.
 Ac – 221
89 protons, 132 neutrons, 89 electrons
 Mg
12 protons, 12 neutrons, 12 electrons
 Rn
86 protons, 136 neutrons, 86 electrons
 Cl – 35
17 protons, 18 neutrons, 17 electrons
What is the average atomic mass of Magnesium if 78.99% is Mg – 24 (23.985 amu), 10% is Mg – 25 (24.986
amu) and 11.01% is Mg – 26 (25.983 amu).
(.7899*23.985) + (.10*24.986) + (.1101*25.983) =
24.31 amu
(ignore sigfigs)
What does the atomic number tell us about an atom of an element?
The atomic number tells us the number of protons and electrons in a neutral atom.
What does the mass number tell us about an atom?
The mass number tells us the number of protons + neutrons in an atom.
Calculate the Molar Mass of the following:
FeSO4
___151.92 g/mol_____
Ca(C2H3O2)2 ____158.18 g/mol_____
N2
___28.02 g/mol______
Au
____196.97 g/mol_____
(NH4)3PO4
___149.12 g/mol_____
NaNO3
____85.00 g/mol______
Calculate the mass of 3.621 x 1022 molecules of Ca(C2H3O2)2.
Determine the number of helium atoms in 2.25 moles of helium.
Calculate the number of moles in 55.372 grams of boron.
What happens to an atom during ionization and why do atoms undergo this change?
Atoms gain or lose electrons during ionization. Atoms undergo this change to become more stable.
What is a Cation?
A cation is a positively charged ion. It results from the loss of electrons.
What is an Anion?
An anion is a negatively charged ion. It results from an atom gaining electrons.
Determine the number of protons, neutrons and electrons in each of the following atoms:
Mg+2
12 protons, 12 neutrons, 10 electrons
P-3
15 protons, 16 neutrons, 18 electrons
Cl-37-1
17 protons, 20 neutrons, 18 electrons
What is Radioactive Decay?
Radioactive decay is the spontaneous decay of a nucleus into a more stable nucleus due to the emission of
radioactive particles or energy.
What are the three forms of decay? How does each change the # subatomic particles in the atom? How does
each type change the mass # and atomic #?
Alpha decay – decreases number of protons (atomic number) by 2, decreases number of neutrons by 2, mass
decreases by 4
Beta decay – decreases the number of neutrons by 1, increases the number of protons (atomic number) by one,
and as a result the mass stays the same.
Gamma decay – a form of energy given off which results in no change in protons, neutrons, or mass.
What is the Daughter Isotope produced from each of the changes below?
What form of decay occurs between the parent and the daughter isotope? Alpha or Beta?
Beta
Alpha
Alpha
Complete the following chart:
Symbol
2H
Name
Hydrogen-2
Mass #
Atomic #
p+
no
e-
Charge
2
1
1
1
1
0
19F
fluorine-19
19
9
9
10
9
0
84Kr
Krypton-84
84
36
36
48
36
0
235U
Uranium-235
235
92
92
143
92
0