Question

Question 6(Multiple Choice Worth 3 points)
(06.02 MC)

Electrolysis uses electrical current to break water molecules into oxygen gas and hydrogen gas. How do you know that this is a chemical change?

Chemical bonds in the water molecule are broken.
There is a phase change from liquid to gas.
Electrical current always causes a chemical change.
It is a single replacement reaction.
Question 7(Multiple Choice Worth 3 points)
(06.03 MC)

Which property of matter allows convection currents to form?

Fluids rise if they are less dense than the matter around them.
The molecules in solids do not vibrate very quickly.
Electromagnetic waves carry energy.
Liquids take the shape of their container.
Question 8(Multiple Choice Worth 3 points)
(06.06 MC)

Which would you most expect to be an unstable atom?

A carbon (C) atom with 6 protons and 6 neutrons
An iron (Fe) atom with 26 protons and 27 neutrons
A helium (He) atom with 2 protons and 2 neutrons
A curium (Cm) atom with 96 protons and 85 neutrons
Question 9(Multiple Choice Worth 3 points)
(06.06 MC)

Which is one way to determine whether a reaction was a chemical reaction or a nuclear reaction?

Check for a change in total mass during the reaction.
Check to see if any energy was released during the reaction.
Measure the temperature change during the reaction.
Measure the total volume of gas released during the reaction.
Question 10(Multiple Choice Worth 3 points)
(06.05 MC)

A student performs an experiment to see how catalysts affect the rate of a reaction. He notices that when the reaction is nearly finished, it stops bubbling. He wants to know how much faster the reaction occurs when a catalyst is used. Which is the best method for him to measure his data?

Use a stopwatch to record the time it takes for the bubbling to stop.
Estimate the time of the reaction by counting aloud.
Count the number of bubbles formed by the reaction.
Measure the size of the bubbles produced with a ruler.
Question 11(Multiple Choice Worth 3 points)
(06.03 MC)

A physical science student is describing the characteristics of endothermic reactions, and creates the following table.


Endothermic
Energy must be absorbed from the surroundings.
Products have a higher potential energy than reactants.
Example is building biomass.
Reactants have more energy than products.

Which statement best corrects the table?
Products have a lower potential energy than reactants.
Reactants have a higher potential energy than products.
Example is photosynthesis.
Energy is released.
Question 12(Multiple Choice Worth 3 points)
(06.05 MC)

A student analyzes soil samples from her backyard. She organizes the samples into three categories, based on their pH. The three categories are: pH less than 8, pH between 8 and 8.5, pH greater than 8.5. Which type of graph should she use to show the percent of samples in each group?

Stem and leaf plot
Circle graph
Line graph
Scatter plot
Question 13(Multiple Choice Worth 3 points)
(06.05 MC)

Ammonia is an important ingredient in many fertilizers. The main process by which ammonia is made is the Haber process. In this process, nitrogen gas and hydrogen gas are reacted to form ammonia at high temperatures. Which of the following most likely explains why this reaction is carried out at high temperatures?

Ammonia is unstable at room temperature.
High temperatures increase the activation energy of the reaction.
High temperatures make the gas molecules move more quickly.
The reaction becomes exothermic at high temperatures.
Question 14(Multiple Choice Worth 3 points)
(06.01 LC)

How many different types of atoms are present in one molecule of aluminum hydroxide, Al(OH)3?

2
3
4
5
Question 15(Multiple Choice Worth 3 points)
(06.01 LC)

Which molecule contains the smallest number of hydrogen atoms?

N2H4
Al(OH)3
(NH4)2SO4
NH4NO3
Question 16(Multiple Choice Worth 3 points)
(06.06 LC)

Why are reactions that emit alpha particles generally considered more safe than those that emit beta particles?

Beta particles emit gamma rays.
Alpha particles have no charge.
Beta particles travel at a very low speed.
Alpha particles can be blocked very easily.
Question 17(Multiple Choice Worth 3 points)
(06.05 MC)

A student performs the reaction shown below:
NaOH + HCl → NaCl + H2O

She increases the concentrations of NaOH and HCl, and finds that NaCl is produced much more quickly. Which explains the outcome of her experiment?

NaOH and HCl molecules collide more frequently at higher concentrations.
NaCl requires a high concentration for any reaction to occur.
HCl acts as a catalyst, but only at high concentrations.
The higher concentrations create a higher temperature in the solution.
Question 18(Multiple Choice Worth 3 points)
(06.03 MC)

A red-hot piece of iron is set on a metal workbench. A student says that it transfers heat to the bench and the air by conduction, and that no other heat transfer takes place. What is wrong with the student's reasoning?

Metal cannot transfer heat by conduction.
Conduction does not work between a solid and a gas.
The metal also gives off heat in the form of radiation.
The iron convects heat to the workbench.
Question 19(Multiple Choice Worth 3 points)
(06.03 MC)

What must be true for any endothermic reaction?

There are more products than there are reactants.
There must be a phase change from solid to liquid or from liquid to gas.
The reaction must take place in a sealed container held at constant volume.
The chemical bonds of the products have more energy than the chemical bonds of the reactants.

Answer 1

Here are the answers to your questions:

Question 6: The correct answer is **Chemical bonds in the water molecule are broken.**

Question 7: The correct answer is **Fluids rise if they are less dense than the matter around them.**

Question 8: The correct answer is **A curium (Cm) atom with 96 protons and 85 neutrons.**

Question 9: The correct answer is **Check for a change in total mass during the reaction.**

Question 10: The correct answer is **Use a stopwatch to record the time it takes for the bubbling to stop.**

Question 11: The correct answer is **Example is photosynthesis.**

Question 12: The correct answer is **Circle graph.**

Question 13: The correct answer is **High temperatures make the gas molecules move more quickly.**

Question 14: The correct answer is **3.** (Aluminum, oxygen, and hydrogen)

Question 15: The correct answer is **Al(OH)3.**

Question 16: The correct answer is **Alpha particles can be blocked very easily.**

Question 17: The correct answer is **NaOH and HCl molecules collide more frequently at higher concentrations.**

Question 18: The correct answer is **The metal also gives off heat in the form of radiation.**

Question 19: The correct answer is **The chemical bonds of the products have more energy than the chemical bonds of the reactants.**

Feel free to ask if you need further explanation on any of the answers!