Multi-Module Exam 1-3: Answers 12/10/20, 11:12 PM
CHEM 130 Multi-Module Exam 1-3:
Questions and Answers + rationales with
100% accuracy
Due Dec 18 by 11:59pm Points None
Available Nov 2 at 12am - Dec 18 at 11:59pm about 2 months
Here are the answers to the Exam. Calculations steps are shown below the problems that
have calculations. Please remember to use the periodic table assigned to this class or
answers will not calculate correctly
Q1: Fill in the blanks
1. There are 11 on the periodic table that occur as gases at environmentally normal
temperature and pressure and 2 elements that occur as liquids. The remaining elements
in the periodic table are solids.
2. has 48 more neutrons than it has number of indicating that it is an isotope of
strontium
3. From the periodic table we can see that 2.500 moles of Zinc (Zn) has a mass of 163.5
grams. (Be sure to use the correct number of significant figures in your answer)
How to calculate the answer to #3...
Step 1: Find the molar mass of Zn on the periodic table
1 mol Zn = 63.38 g
Step 2: Do the conversion using unit factoring. The answer can only have four significant
figures
https://learn.maricopa.edu/courses/1156356/assignments/10147780 Page 1 of 5
,Multi-Module Exam 1-3: Answers 12/10/20, 11:12 PM
Q2: Indicate true or false for the following statements:
1. FALSE - Aluminum (Al) will normally make three covalent bonds with other atoms in a
compound
Reason: Please note that Al is a metal so does not normally make covalent bond...only ionic
bonds
2. FALSE - An ionic bond is made up of two shared electrons...one contributed from each of
the participating atoms
participating atoms
Reason: Ionic bonds do not share electrons. The participating electrons are given/taken
completely to form ions
3. TRUE - A covalent bond is usually made between two atoms that are non-metals
4. FALSE - The octet rule states that all atoms (except H and He) are more stable with 8
electrons in their d sub levels
Reason: Valence electrons are in the s & p sublevels only...not in the d sublevel
5. TRUE - By looking at the Lewis diagram of an oxygen molecule (O2) we can tell that the
two O atoms are joined by two covalent bonds between each other
Q3: How many valence shell electrons does an atom of each of the following elements
have?
1. Selenium (Se) = 6 valence shell electrons
2. Cobalt (Co) = 2 valence shell electrons
3. Chlorine (Cl) = 7 valence shell electrons
4. Barium (Ba) = 2 valence shell electrons
5. Aluminum (Al) = 3 valence shell electrons
https://learn.maricopa.edu/courses/1156356/assignments/10147780 Page 2 of 5
, Multi-Module Exam 1-3: Answers 12/10/20, 11:12 PM
Q4: What are the following relationships between units?
1 x 10-6 (or 0.000001) Gg = 1.0 kg
1 x 106 (or 1000000) mm = 1.0 km
1 x 103 (or 1000) = 1.0 L
1 x 103 (or 1000) g = 1.0 ng
1 x 10-9 (or 0.000000001) mL = 1.0 pL
Q5: Which is the smallest temperature increase 10 Kelvins (such as 100K to 110K) or 10
degrees F (such as 100F to 110F)?
Answer: 10 degrees F is smaller
Reason: The relationship between Kelvins and degrees F is...1 K = 1.8 degrees F...so a degree
F is nearly twice as small as a Kelvin
Q6: Write 8.504 x 10-4 in standard form
Answer: 0.0008504
Q7: Assume you do a calculation in chemistry class and when you punch in the numbers
to your calculator and hit the "=" button you get 52.3628455102 as the answer. Explain
why this number is generally considered to be not correct in science.
Answer (should have something similar to this): The numbers on a calculator show the
answer to mathematical operations on various numbers and does not reflect the accuracy
and precision that are part of the measured values used in the calculation. For this we have
to round to the correct number of significant figures in order to have an value that is correct.
https://learn.maricopa.edu/courses/1156356/assignments/10147780 Page 3 of 5
CHEM 130 Multi-Module Exam 1-3:
Questions and Answers + rationales with
100% accuracy
Due Dec 18 by 11:59pm Points None
Available Nov 2 at 12am - Dec 18 at 11:59pm about 2 months
Here are the answers to the Exam. Calculations steps are shown below the problems that
have calculations. Please remember to use the periodic table assigned to this class or
answers will not calculate correctly
Q1: Fill in the blanks
1. There are 11 on the periodic table that occur as gases at environmentally normal
temperature and pressure and 2 elements that occur as liquids. The remaining elements
in the periodic table are solids.
2. has 48 more neutrons than it has number of indicating that it is an isotope of
strontium
3. From the periodic table we can see that 2.500 moles of Zinc (Zn) has a mass of 163.5
grams. (Be sure to use the correct number of significant figures in your answer)
How to calculate the answer to #3...
Step 1: Find the molar mass of Zn on the periodic table
1 mol Zn = 63.38 g
Step 2: Do the conversion using unit factoring. The answer can only have four significant
figures
https://learn.maricopa.edu/courses/1156356/assignments/10147780 Page 1 of 5
,Multi-Module Exam 1-3: Answers 12/10/20, 11:12 PM
Q2: Indicate true or false for the following statements:
1. FALSE - Aluminum (Al) will normally make three covalent bonds with other atoms in a
compound
Reason: Please note that Al is a metal so does not normally make covalent bond...only ionic
bonds
2. FALSE - An ionic bond is made up of two shared electrons...one contributed from each of
the participating atoms
participating atoms
Reason: Ionic bonds do not share electrons. The participating electrons are given/taken
completely to form ions
3. TRUE - A covalent bond is usually made between two atoms that are non-metals
4. FALSE - The octet rule states that all atoms (except H and He) are more stable with 8
electrons in their d sub levels
Reason: Valence electrons are in the s & p sublevels only...not in the d sublevel
5. TRUE - By looking at the Lewis diagram of an oxygen molecule (O2) we can tell that the
two O atoms are joined by two covalent bonds between each other
Q3: How many valence shell electrons does an atom of each of the following elements
have?
1. Selenium (Se) = 6 valence shell electrons
2. Cobalt (Co) = 2 valence shell electrons
3. Chlorine (Cl) = 7 valence shell electrons
4. Barium (Ba) = 2 valence shell electrons
5. Aluminum (Al) = 3 valence shell electrons
https://learn.maricopa.edu/courses/1156356/assignments/10147780 Page 2 of 5
, Multi-Module Exam 1-3: Answers 12/10/20, 11:12 PM
Q4: What are the following relationships between units?
1 x 10-6 (or 0.000001) Gg = 1.0 kg
1 x 106 (or 1000000) mm = 1.0 km
1 x 103 (or 1000) = 1.0 L
1 x 103 (or 1000) g = 1.0 ng
1 x 10-9 (or 0.000000001) mL = 1.0 pL
Q5: Which is the smallest temperature increase 10 Kelvins (such as 100K to 110K) or 10
degrees F (such as 100F to 110F)?
Answer: 10 degrees F is smaller
Reason: The relationship between Kelvins and degrees F is...1 K = 1.8 degrees F...so a degree
F is nearly twice as small as a Kelvin
Q6: Write 8.504 x 10-4 in standard form
Answer: 0.0008504
Q7: Assume you do a calculation in chemistry class and when you punch in the numbers
to your calculator and hit the "=" button you get 52.3628455102 as the answer. Explain
why this number is generally considered to be not correct in science.
Answer (should have something similar to this): The numbers on a calculator show the
answer to mathematical operations on various numbers and does not reflect the accuracy
and precision that are part of the measured values used in the calculation. For this we have
to round to the correct number of significant figures in order to have an value that is correct.
https://learn.maricopa.edu/courses/1156356/assignments/10147780 Page 3 of 5
