Which statement correctly compares barium nitrate (Ba(NO3)2) and scandium nitrate (Sc(NO3)3)?
They contain the same number of NO3 groups.
They contain the same number of oxygen atoms.
They contain the same total number of atoms.
They contain the same number of elements.
Question 2 (Multiple Choice Worth 2 points)
Why is water considered a polar molecule?
The molecule has no overall charge.
The oxygen and hydrogen atoms share electrons equally.
The atoms in the molecule have partial charges.
The molecule can only attract positive charges.
Question 3 (Essay Worth 5 points)
A student tested a sample of carbon (C) by combining it with water. There was no reaction between the carbon and water. The student concluded that carbon must be a group 18 element, since it was unreactive. State whether you agree with the student's reasoning, and explain why or why not.
Question 4 (Multiple Choice Worth 2 points)
Which is most closely related to the color of an acid–base indicator when dipped into solution?
the hydronium ion concentration in the solution
the total amount of solution present
the number of water molecules in the solution
the mass of undissolved solids in the solution
Question 5 (Multiple Choice Worth 2 points)
Which best describes how a pH test strip works?
Molecules in the paper react differently with hydronium and hydroxide ions.
The paper dissolves when placed in acids, but not when placed in bases.
Polar molecules affect the paper differently than nonpolar molecules.
The paper uses the low surface tension of water to attract acidic particles.
Question 6 (Multiple Choice Worth 2 points)
What do elements in the first two columns of the periodic table have in common?
They have two valence electrons.
They tend to lose electrons to gain stability.
They react strongly with the alkali metals.
They do not react with halogens.
Question 7 (Multiple Choice Worth 2 points)
What do all group 2 elements have in common?
They all gain two electrons to form a stable outer energy level.
They form covalent bonds with halogens.
They all react easily with the noble gases.
They tend to form ionic bonds by losing electrons.
Question 8 (Multiple Choice Worth 2 points)
A scientist observes that after mixing a solid powder into water, the pH of the newly formed solution is 2.7. What can he infer from this observation?
The solution contains an indicator that has a pH of 2.7.
The solid powder contained hydrogen ions.
The pH indicator was used incorrectly.
The powder increased the hydrogen ion concentration of the solution.
Question 9 (Multiple Choice Worth 2 points)
How could a student determine whether an unknown chemical is an acid?
Test the hydrogen ion concentration in the sample.
Measure the boiling point of the sample.
Weigh the sample before and after adding salt.
Determine whether the sample has surface tension.
Question 10 (Multiple Choice Worth 2 points)
How many different elements make up beryllium sulfite, BeSO3?
1
3
4
5
Question 11 (Multiple Choice Worth 2 points)
How many total atoms are in one molecule of lithium nitrate, LiNO3?
1
3
5
7
Question 12 (Multiple Choice Worth 2 points)
Which of the following questions could most likely be answered using molecular clocks?
Which species of beetles are most closely related?
How many species of beetles existed in the past?
What processes cause beetles to become extinct?
How long have beetles existed on Earth?
Question 13 (Multiple Choice Worth 2 points)
What does the position of lithium on the periodic table tell you about its tendency to react with other elements?
It is in the second row, so it tends to gain two electrons.
It is in the second row, so it tends to lose two electrons.
It is in the first column, so it tends to lose one electron.
It is in the first column, so it tends to gain one electron.
Question 14 (Multiple Choice Worth 2 points)
Which results from water’s formation of hydrogen bonds?
Water has surface tension.
Hydrogen and oxygen form ionic bonds.
Water is a versatile solvent.
The specific heat of water is lower than most solids.
Question 15 (Multiple Choice Worth 2 points)
Which is a correct method used in a scientific experiment involving acid and base solutions?
using a pH test strip to measure the oxygen content of a solution
adding an indicator to a solution to test its acidity
adjusting the recorded pH measurements to prove the hypothesis
measuring the pH of a test strip by dipping it into an indicator
Question 16 (Multiple Choice Worth 2 points)
A student had a sample of pure water, and added an unknown substance to it. The student noticed that the hydroxide ion concentration in the solution increased as the substance was added. What is true about this newly formed solution?
It is basic.
They contain the same number of NO3 groups.
They contain the same number of oxygen atoms.
They contain the same total number of atoms.
They contain the same number of elements.
Question 2 (Multiple Choice Worth 2 points)
Why is water considered a polar molecule?
The molecule has no overall charge.
The oxygen and hydrogen atoms share electrons equally.
The atoms in the molecule have partial charges.
The molecule can only attract positive charges.
Question 3 (Essay Worth 5 points)
A student tested a sample of carbon (C) by combining it with water. There was no reaction between the carbon and water. The student concluded that carbon must be a group 18 element, since it was unreactive. State whether you agree with the student's reasoning, and explain why or why not.
Question 4 (Multiple Choice Worth 2 points)
Which is most closely related to the color of an acid–base indicator when dipped into solution?
the hydronium ion concentration in the solution
the total amount of solution present
the number of water molecules in the solution
the mass of undissolved solids in the solution
Question 5 (Multiple Choice Worth 2 points)
Which best describes how a pH test strip works?
Molecules in the paper react differently with hydronium and hydroxide ions.
The paper dissolves when placed in acids, but not when placed in bases.
Polar molecules affect the paper differently than nonpolar molecules.
The paper uses the low surface tension of water to attract acidic particles.
Question 6 (Multiple Choice Worth 2 points)
What do elements in the first two columns of the periodic table have in common?
They have two valence electrons.
They tend to lose electrons to gain stability.
They react strongly with the alkali metals.
They do not react with halogens.
Question 7 (Multiple Choice Worth 2 points)
What do all group 2 elements have in common?
They all gain two electrons to form a stable outer energy level.
They form covalent bonds with halogens.
They all react easily with the noble gases.
They tend to form ionic bonds by losing electrons.
Question 8 (Multiple Choice Worth 2 points)
A scientist observes that after mixing a solid powder into water, the pH of the newly formed solution is 2.7. What can he infer from this observation?
The solution contains an indicator that has a pH of 2.7.
The solid powder contained hydrogen ions.
The pH indicator was used incorrectly.
The powder increased the hydrogen ion concentration of the solution.
Question 9 (Multiple Choice Worth 2 points)
How could a student determine whether an unknown chemical is an acid?
Test the hydrogen ion concentration in the sample.
Measure the boiling point of the sample.
Weigh the sample before and after adding salt.
Determine whether the sample has surface tension.
Question 10 (Multiple Choice Worth 2 points)
How many different elements make up beryllium sulfite, BeSO3?
1
3
4
5
Question 11 (Multiple Choice Worth 2 points)
How many total atoms are in one molecule of lithium nitrate, LiNO3?
1
3
5
7
Question 12 (Multiple Choice Worth 2 points)
Which of the following questions could most likely be answered using molecular clocks?
Which species of beetles are most closely related?
How many species of beetles existed in the past?
What processes cause beetles to become extinct?
How long have beetles existed on Earth?
Question 13 (Multiple Choice Worth 2 points)
What does the position of lithium on the periodic table tell you about its tendency to react with other elements?
It is in the second row, so it tends to gain two electrons.
It is in the second row, so it tends to lose two electrons.
It is in the first column, so it tends to lose one electron.
It is in the first column, so it tends to gain one electron.
Question 14 (Multiple Choice Worth 2 points)
Which results from water’s formation of hydrogen bonds?
Water has surface tension.
Hydrogen and oxygen form ionic bonds.
Water is a versatile solvent.
The specific heat of water is lower than most solids.
Question 15 (Multiple Choice Worth 2 points)
Which is a correct method used in a scientific experiment involving acid and base solutions?
using a pH test strip to measure the oxygen content of a solution
adding an indicator to a solution to test its acidity
adjusting the recorded pH measurements to prove the hypothesis
measuring the pH of a test strip by dipping it into an indicator
Question 16 (Multiple Choice Worth 2 points)
A student had a sample of pure water, and added an unknown substance to it. The student noticed that the hydroxide ion concentration in the solution increased as the substance was added. What is true about this newly formed solution?
It is basic.