Both gases and liquids are considered to be fluids that have individual molecules that move around with kinetic and potential energy. Kinetic energy, defined as the energy related to motion, takes three forms: translational energy that occurs as a molecule moves from position A to position B, rotational energy that occurs as a molecule spins around an imaginary axis at its center of mass, and vibrational energy that occurs as individual atoms in a molecular bond move towards and away from each other. Usually, molecules possess varying combinations of kinetic energy forms. In contrast, potential energy is defined as stored energy that could be released to become kinetic energy. The total energy of a molecule is fixed, meaning that a molecule has some combination of kinetic and potential energies.

Varying amount of kinetic and potential energies define how molecules in a fluid interact with each other. For example, when the kinetic energy of a molecule is high (greater than 1000J), it can no longer interact with neighboring molecules strongly enough to remain a liquid. However, if the potential energies are too high (greater than 1000 J), molecules cannot escape a liquid to become a gas. If the kinetic energy is high and the potential energy is low, molecules tend to become a gas and can be modeled by an equation known as the Ideal Gas Law:

Where P is the pressure of a gas, V is the volume, n is the number of moles of a gas, R is a constant, and T is temperature in degrees Kelvin.

The Ideal Gas Law perfectly applies to particles with no mass, no intermolecular interactions, and no true volume. However, real molecules do not adhere perfectly to the Ideal Gas Law.

The relationship between total energy, kinetic energy, and potential energy could best be described as:

A chemist has mixed up the labels on some of his chemical compounds. To try to determine the compounds, the chemist dissolves the compounds in pure water. He notes the corrosiveness and color of each solution, along with a measurement of the pH for each (for which he estimates a 0.15 margin of error for each measurement).

Does this set of experiments achieve its goal?

Kevin wants to know if a particular kind of chemical fertilizer will help or hinder the growth of his tomato plants. He decides to conduct an experiment in which he grows three plants, one left untreated, one treated with the chemical fertilizer RapidGro and one treated with an organic compost. He records his findings in the charts below, measuring plant height and number of tomatoes over a period of time.

Height of plant (inches):

Number of tomatoes:

On the fourteenth day Kevin picks the biggest tomato from each plant and record its dimensions, as well as other information, which is found below.

Tomato 1 (no fertilizer): in diameter, dull red, lumpy in shape, wormholes, flavorful.

Tomato 2 (RapidGro): in diameter, shiny red, round, somewhat tasteless.

Tomato 3 (compost): in diameter, deep red, lumpy shape, very flavorful.

What could have happened to plant 2 between days 10 and 14?

A student wants to perform an experiment which tests the relationship between the pressure of a gas and the volume it occupies. To perform this experiment, the student places a specific type of gas in a sealed chamber that can change pressure and which can adapt its volume to the gas within it. The chamber also adjusts to the changing pressure such that the temperature (which also has an effect on gas volume) does not change. The following data was obtained:

In a second experiment, the student tries the same experiment described in the pre-question text and uses a different gas for each trial. If the readings for volume yielded the same results, what could be said about the relationship between type of gas and volume?

The Millikin oil drop experiment is among the most important experiments in the history of science. It was used to determine one of the fundamental constants of the universe, the charge on the electron. For his work, Robert Millikin won the Nobel Prize in Physics in 1923.

Millikin used an experimental setup as follows in Figure 1. He opened a chamber of oil into an adjacent uniform electric field. The oil droplets sank into the electric field once the trap door opened, but were then immediately suspended by the forces of electricity present in the field.

Figure 1:

By determining how much force was needed to exactly counteract the gravity pulling the oil droplet down, Millikin was able to determine the force of electricity. This is depicted in Figure 2.

Using this information, he was able to calculate the exact charge on an electron. By changing some conditions, such as creating a vacuum in the apparatus, the experiment can be modified.

Figure 2:

When the drop is suspended perfectly, the total forces up equal the total forces down. Because Millikin knew the electric field in the apparatus, the force of air resistance, the mass of the drop, and the acceleration due to gravity, he was able to solve the following equation:

Table 1 summarizes the electric charge found on oil drops in suspension. Millikin correctly concluded that the calculated charges must all be multiples of the fundamental charge of the electron. A hypothetical oil drop contains some net charge due to lost electrons, and this net charge cannot be smaller than the charge on a single electron.

Table 1:

The electric force experienced by oil drops will vary directly with the magnitude of charge on the drop. A scientist is measuring two different drops in two different experimental apparatuses, but each in perfect suspension and not moving. Drop 1 has a greater net charge than does drop 2. The magnitude of the electric force:

A scientist decided to use high-tech equipment to measure the electronegativity, an atom's attraction to electrons, of the second period on the periodic table. The results of her measurements are in the chart below. Z is equal to the atomic number of the specified atom and the number of protons in that atom.

Metals are elements that typically have electronegativities of less than 2.0 Debyes. Which of the following sets of atoms do not contain a metal?

Kevin wants to know if a particular kind of chemical fertilizer will help or hinder the growth of his tomato plants. He decides to conduct an experiment in which he grows three plants, one left untreated, one treated with the chemical fertilizer RapidGro and one treated with an organic compost. He records his findings in the charts below, measuring plant height and number of tomatoes over a period of time.

Height of plant (inches):

Number of tomatoes:

On the fourteenth day Kevin picks the biggest tomato from each plant and record its dimensions, as well as other information, which is found below.

Tomato 1 (no fertilizer): in diameter, dull red, lumpy in shape, wormholes, flavorful.

Tomato 2 (RapidGro): in diameter, shiny red, round, somewhat tasteless.

Tomato 3 (compost): in diameter, deep red, lumpy shape, very flavorful.

What information might have been helpful to Kevin while gathering his data?

Kevin wants to know if a particular kind of chemical fertilizer will help or hinder the growth of his tomato plants. He decides to conduct an experiment in which he grows three plants, one left untreated, one treated with the chemical fertilizer RapidGro and one treated with an organic compost. He records his findings in the charts below, measuring plant height and number of tomatoes over a period of time.

Height of plant (inches):

Number of tomatoes:

On the fourteenth day Kevin picks the biggest tomato from each plant and record its dimensions, as well as other information, which is found below.

Tomato 1 (no fertilizer): in diameter, dull red, lumpy in shape, wormholes, flavorful.

Tomato 2 (RapidGro): in diameter, shiny red, round, somewhat tasteless.

Tomato 3 (compost): in diameter, deep red, lumpy shape, very flavorful.

What might make it difficult for Kevin to draw a conclusion about the plants?

A scientist decided to use high-tech equipment to measure the electronegativity, an atom's attraction to electrons, of the second period on the periodic table. The results of her measurements are in the chart below. Z is equal to the atomic number of the specified atom and the number of protons in that atom.

An atom's atomic radius tends to follow an opposite trend than electronegativity with regards to an atom's atomic number. Which of the following pairs of atoms does not involve an atom with a larger radius followed by an atom with a smaller radius?

Clock reactions are chemical interactions that exhibit a physical change periodically over a given time interval. Many of these reactions involve iodine, the most famous being the Chlorine Dioxide-Iodine-Malonic Acid reaction. These reactions can be quite startling as flasks of colorless liquid periodically turn dark blue and then resolve back to their original colorless state. Even more striking, they seem to alternate between being colorless and blue several times. The term "clock reaction" is derived from the fact that the time at which these sudden changes occur can be predicted.

Beyond performing these reactions in a well stirred beaker, there are two other notable ways to conduct experiments with clock reactions that demonstrate interesting properties of these reactions. The first is in a continuous flow stirred tank reactor (CSTR). In a CSTR, the reactants are introduced at a continuous rate while the volume of liquid in the reactor is kept constant by siphoning off excess fluid. The result of this process is that one can maintain the ideal conditions in which the reaction may occur over time and restricts the buildup of excess product or reactant that would otherwise make the oscillations of the reactions decay. In a CSTR, clock reactions can be maintained switching predictably from colorless to blue, for example, for far longer than in a simple beaker.

The second way to conduct a clock reaction experiment is in a tank with no stirring at all. This allows the reactants to interact heterogeneously, or without being thoroughly mixed. When this occurs, we can get some parts of the tank that are one color and other parts that are another color. This means that we can observe two different stages of the reaction in one vessel. The patterns that this makes are called Turing patterns, named by the great computer scientist Alan Turing. Turing predicted that the heterogeneous mixing of chemicals called morphogens in complex organisms were responsible for biological pattern formation like spots on a leopard, stripes on a zebra, or patterns on a tropical fish. The existence of such patterns and chemicals has since been confirmed and clock reactions are often used to study these types of Turing patterns.

Which of the following would Turing have agreed was predicted by his morphogen theory?