2.5.
1 Practice: Atomic Structure Practice
Chemistry Honors Sem 1 Name:Warren Boyce
Date:10/14/24
Question 1: Laws of Conservation of Matter and Energy (2
points)
a. Law of conservation of matter (1 point)
i. What does the law say about matter?
Matter cannot be made or destroyed.
ii. What about matter can change and what does not change,
according to the law?
The form of the matter can change, but the amount of matter does not
change.
b. Law of conservation of energy (1 point)
i. What does the law say about energy?
It says that energy cannot be destroyed or destroyed.
ii. What about energy can change and what does not change,
according to the law?
The energy can change forms, however the total amount of energy
cannot change.
Question 2: Phases of Matter (2 points)
a. What are the four states, or phases, of matter? Describe the shape
and volume properties of each phase. Can they change, or are they
fixed? (1 point)
i. _______solid________________
Shape: fixed
Volume: fixed
ii. _____liquid__________________
Shape: forms to the shape of its container
Volume: fixed
iii. _____gas__________________
Shape: takes the shape of its container
Volume: takes the volume of its container
iv. ___plasma____________________
Shape: takes the shape of its container
Volume: takes the volume of its container
b. When heat energy is absorbed by matter, the matter's temperature
increases. When heat energy is released by matter, the matter's
temperature decreases. The matter can also change from one phase to
another when heat energy is absorbed or released. Identify whether
matter absorbs heat or releases heat as each of the following phase
changes occur. (1 point)
i. From solid to liquid (melting)
absorbed
ii. From liquid to solid (freezing or hardening)
released
iii. From liquid to gas (evaporation)
absorbed
iv. From gas to liquid (condensation)
released
Question 3: Types of Energy (4 points)
a. List four kinds of energy. Give a brief definition of each. (1 point)
i. ________Kinetic energy: energy being possessed through motion
______________________________________________________
ii. ___potential energy: energy being stored due to its state or
position___________________________________________________________
iii. __chemical energy: energy stored in the bonds of chemical
compounds____________________________________________________________
iv. ___thermal energy: energy coming from temperature of
matter___________________________________________________________
b. Energy can change from one form to another. Describe the
energy conversions in the following scenes. (1 point)
i. A kid falling out of a tree
Potential energy to kinetic energy
ii. A scout rubbing sticks together to start a fire
Mechanical energy to thermal energy
iii. A man running a kerosene heater
chemical energy to thermal energy
c. What is the equation for calculating gravitational potential energy
on the Earth? (1 point)
U = mgh
d. What is the equation for calculating kinetic energy? (1 point)
KE = 1/2mv^2
Read pages 1 – 4 of the practice activity to find information
that will help you answer questions 4 – 6.
Question 4: Potential to Kinetic Energy Conversion (7 points)
All units must be identified throughout your equations and in your
answers.
a. Use the equation for GPE to answer the following questions. (2
points)
i. Explain how the equation for GPE = force distance. (1 point)
The force exerted by gravity on an object is F = m x g, so GPE can be
shown as GPE = FxH
ii. Use the definition of force = mass acceleration to show how
the equation for GPE is in units of joules. (1 points)
fxh = m x g x h
kg x m/s^2 x m = kg x m^2 / s^2
b. Use the equation for KE to answer the following questions. (2
points)
i. Show how the equation for KE has units of joules. (1 point)
kg x m/s^2 = kg x m^2 / s^2
1J = 1kgxm^2/s^2
ii. Show how the equation for KE = force distance. (1 point)
w=fxd
KE = F x d
c. A 75 lb (34 kg) boy falls out of a tree from a height of 10 ft (3 m).
(3 points)
i. What is the kinetic energy of the boy when he hits the ground?
Round your answer to the nearest joule. (1 point)
PE = 75 kg x 9.8m/s^2 x 10m = 7350 J
ii. What is the speed of the boy when he hits the ground? Round
your answer to two significant figures. (1 point)
v = sqrt 2x7350J/75kg = 14 m/s^2
iii. Using the conversion factors of 1 m = 1.094 yd and 1 mi =
1760 yd, calculate the speed of the boy in miles per hour when he
hits the ground. (1 point)
114 m/s^2 x 1.094 yd/m = 15.316 yd/s
15.316 yd/s/1760 yd/mi x 3600s/hr = 31.3 mi/hr
Question 5: Electrical Energy Units (3 points)
a. Replacing standard incandescent lightbulbs with energy-efficient
compact fluorescent lightbulbs can save a lot of energy. Calculate the
amount of energy saved over 10 h when one 60 W incandescent
lightbulb is replaced with an equivalent 18 W compact fluorescent
lightbulb. (2 points)
60 w x 10h = 600 wh
18w x 10hh = 180 wh
600wh – 180 wh =
420 Wh
b. How long could you run a 300 W plasma television set on the
saved energy? (1 point)
420 Wh/300w = 1.4 hours
Question 6: Chemical to Electrical Energy Conversion (6 points)
a. A portable gasoline-powered generator produces electrical energy
from gasoline. If the generator were 100% efficient (that is, 100% of
the energy from the fuel burned is converted to electrical energy), how
much electrical energy in kWh would be generated from 5 gal of
gasoline? The chemical potential energy in gasoline is 1.3 108 J/gal. (1
point)
6.5 x 10^8 J = 180.56 kWh
b. In reality, energy conversion from burning fuel is never 100%
efficient. Significant loss of energy due to heating occurs. If the
generator were only 20% efficient (which is more realistic), how
much energy in joules would be converted to electrical energy and
how much would be lost to heat? (2 points)
5.2 x 10^8 J
c. At 20% efficiency, how many kWh would actually be produced
from the 5 gal of gasoline? How many BTUs of heat would be
released from burning the gasoline? (2 points)
36.11 kWh
d. How long could this (20% efficient) generator supply power to a
1500 W electrical heater with the 5 gal of gas? (1 point)
24.07 hrs
Question 7: Progression of the Atomic Theory (2 points)
a. Match the following scientist with his experiment or contribution. (1
point)
J. J. Thomson
Albert Einstein
Niels Bohr
Ernest Rutherford
John Dalton
Robert Millikan
__________Robert Millikan_________ Oil-drop experiment
John Dalton
___________________ Atomic theory
____________J.J Thomson_______ Cathode ray experiment
________Niels Bohr___________ Model of the atom
_____Ernest Rutherford______________ Gold-foil experiment
______Albert Einstein_____________ Photoelectric effect
b. Match the following scientist with his understanding of the atom. (1
point)
J. J. Thomson
Albert Einstein
Niels Bohr
Ernest Rutherford
John Dalton
Robert Millikan
________John Dalton___________ Matter made of indivisible atoms
___J.J Thomson,________________ Atoms contain negatively charged
particles
____Robert Millikan_______________ Measured the charge of an electron
______Enerst Rutherford_____________ Atoms contain mostly empty
space
_____Niels Bohr______________ Atoms contain nuclei with electrons
orbiting
_______Albert Einstein____________ Light exists as photon packets; one
photon can remove one electron from an atom
Question 8: The Periodic Table (9 points)
a. Who made the first periodic table? (1 point)
Dmitri Mendeleev
b. On the periodic table, what three pieces of information are given
about every element? (1 point)
i. ______Atomic Number_____________________
• Where is it written?
Top, above the chemical symbol
• What information does it give?
number of protons in the nucleus
ii. ____Chemical symbol_______________________
• Where is it written?
middle
• What information does it give?
abbreviation of the elements name
iii. ____Atomic mass_______________________
• Where is it written?
at the bottom
• What information does it give?
the average mass of the element
c. What are isotopes? (1 point)
Atoms that have the same amount of protons but a different amount of
neutrons
d. What are ions? (1 point)
atoms that have lost or a gained electrons, which means it has a net
positive or negative charge.
e. What are valence electrons, and why are they important? (1
point)
The electrons on the outer most shell of the atom, and they are
important because the number of valence electron an atom has,
determines how reactive it is.
f. What is significant about the elements within the same group of
the periodic table? (1 point)
They have the same amount of valence electrons.
g. What is significant about the elements within the same period of
the periodic table? (1 point)
They have the same amount of electron shells.
h. Match the following families with their properties. There are two
properties for each family. (1 point)
A. Alkali metals
B. Alkaline earth metals
C. Halogens
D. Noble gases
__C____ Very reactive nonmetals
__D____ 8 valence electrons
__A____ 1 valence electron
__B____ Reactive metals
__B____ 2 valence electrons
____C__ 7 valence electrons
_D_____ Very little reactivity
__A____ Very reactive metals
i. What three families are found in the center portion of the periodic
table? (1 point)
1. __Transition metals_______________________
2. ____lanthanides_____________________
3. _____actinides____________________
Question 9: Using the Periodic Table (5 points)
a. An atom has a mass number of 19 and an atomic number of 9. What
element is it? What is its symbol? How many protons, neutrons, and
electrons does it have? (1 point)
Its Fluorine, its symbol is F, it has 9 protons, 10 neutrons, and 9
electrons.
b. Hydrogen has one proton in its nucleus but exists as three
isotopes. One isotope has no neutrons, one has one neutron, and
one has two neutrons. How would they be identified using isotope
notation? (1 point)
1H
2H
3H
c. Sodium chloride, table salt, forms ions when dissolved. Sodium
(Na) loses one electron. Chloride (Cl) gains one electron. What are
the charges on the two ions? (1 point)
sodium ion has a charge of +1 and the chloride ion has a charge of -
1.
d. Would beryllium (Be) or sodium (Na) have properties more similar
to magnesium (Mg)? Why? (1 point)
Be would have more properties to Mg because they are un the same
group.
e. Does beryllium (Be) or sodium (Na) have the same inside electron
arrangement as magnesium (Mg)? Why? (1 point)
Be does not have the same indie electron arrangement, however Na
does because they are in the same period.
Copyright © 2019 Apex Learning Inc. Use of this material is subject to Apex Learning's Terms of Use. Any
unauthorized copying, reuse, or redistribution is prohibited. Apex Learning ® and the Apex Learning Logo are
registered trademarks of Apex Learning Inc.
2.5.1 Practice: Atomic Structure
