Federico has two samples of pure water—sample X and sample Y. Sample X has a volume of 1 L, and sample Y has a volume of 10 L. How do the boiling points of these two samples compare?

A 10 g sample of butter will melt at a temperature that is _______ the melting point of a 5 g sample of butter.

A piece of plastic (sample Q), was heated at a constant rate. After 20 minutes of adding heat, the plastic melted. When an identical piece of plastic (sample R), was heated with twice as much heat per minute, the plastic melted in 10 minutes.

How do the melting points of the two pieces of plastic compare?

Each student in Ms. Major's class was given an unknown substance. Ms. Major gave her students a list, shown below, of substances and their properties to help them identify their unknown.

If a student's unknown is a white solid and its density was calculated to be about 1.7 g/mL, it is most likely _______.

What is the identity of a sample that has a volume of 0.56 cm3 and a mass of 10.8 g?

True or false. Gas particles never touch each other.

What state of matter is best represented by the diagram below?

When substances go through chemical changes, which of the following will always happen?

Mario places 10 mL of water in a test tube and heats the liquid over a Bunsen burner for 2 minutes. After removing the test tube from the Bunsen burner, there are 6 mL of water left in the test tube. This experiment is a good example of a

The chemical reaction shown above takes place in a closed system. What is true about the system while the reaction occurs?

The periodic table is shown below.

Helium (He), neon (Ne) and argon (Ar) are all colorless, odorless gases with low chemical reactivity. Based on the periodic table, which other element would also have those same properties? (Select all of the correct answers below)

The periodic table is shown below.

Based on the periodic table, which of the following groups of elements should have very similar chemical properties?

Neon is a gas made up of only one type of atom. Which term best describes neon?

Within an atom, electrons

What is the smallest part of an element that still retains properties of that element?

Which of the following make up the nucleus of an atom?

All atoms of the same element have the same number of ___________, which is called the atomic number.

Matter can be found existing in several different forms. The image above represents which of the following types of matter?

Matter can be found existing in several different forms. Air is a substance that contains elements and compounds such as oxygen, nitrogen, water vapor and carbon dioxide. Air is an example of which of the following types of matter?

Vinegar has a pH of 2. Vinegar _______.

A solution of baking soda has a pH of 9. Baking soda _______.

A diagram of the carbon-oxygen cycle is shown below.

Which of the following is mainly responsible for the removal of carbon dioxide from the atmosphere?

What principle is used in the above diagram to calculate the amount of carbon dioxide that is absorbed by land?

Living systems consist of organisms interacting with their environments. The carbon cycle is an example of a living system.

Assuming the carbon cycle is a closed system, which of the following statements is true?

The main reason that cells carry out cellular respiration is to _______.

Cellular respiration involves a chemical reaction to form (Select all of the correct answers below)

Photosynthesis involves a chemical reaction between which of following? (Select all of the correct answers below)

The process of cellular respiration begins with molecules of _______ and ends with the production of _______.

Living organisms need energy to carry on their life processes. Green plants get this energy by undergoing photosynthesis.

During photosynthesis, plants absorb energy from sunlight, they take in water from the soil using their roots, and they take in carbon dioxide from the atmosphere. What is produced in the leaves of plants, in addition to oxygen?

Which of the following best describes the matter present in an ecosystem?

Through the process of photosynthesis, light energy from the Sun was transformed into chemical energy in the form of sugar within a strawberry plant. The strawberries were then eaten by a bird, and the sugars were converted into other essential molecules, such as proteins or fats. When the bird produced waste, bacteria in the soil decomposed the waste into elements, such as carbon and nitrogen, which were recycled back into the ecosystem.

In this example, matter and energy changed forms and locations as they flowed through the ecosystem. What else is true?

The diagram below summarizes the Earth's carbon cycle. Examine the diagram, and answer the question that follows.

Carbon is taken from the atmosphere through _______.

The diagram below summarizes the Earth's carbon cycle. Examine the diagram, and answer the question that follows.

Carbon is returned to the atmosphere through _______.

The diagram below shows the Earth, Sun, and Moon system.

From the diagram, which phase of the Moon will result in a spring tide?

The picture below shows the positions of the Earth, Sun, and Moon during an eclipse.

What is true of the eclipse shown in the picture?

The picture below shows the positions of the Earth, Sun, and Moon during an eclipse.

What is true of the eclipse shown in the picture?

As the Earth rotates on its axis and revolves around the Sun, the Earth goes through seasonal changes. Why does this happen?

Different seasons arise as the Earth revolves around the Sun because the Earth's axis is tilted. When the Northern Hemisphere is tilted towards the Sun, what seasons will the two hemispheres be experiencing?

What unit of time on Earth is based on the rotation of the Earth?

What unit of time on Earth is based on the revolution of the Earth around the Sun?

The diagram below shows positions of the Moon as it orbits the Earth.

Half of the Moon's surface is lit by sunlight no matter what the Moon's position, but the amount of the lit surface that is visible from Earth varies with the Moon's position.

Which phase of the Moon is represented by position 1?

The diagram below shows positions of the Moon as it orbits the Earth.

Half of the Moon's surface is lit by sunlight no matter what the Moon's position, but the amount of the lit surface that is visible from Earth varies with the Moon's position.

Which phase of the Moon is represented by position 5?

Tides on Earth occur because of the gravitational force between the Earth, the Moon, and the Sun. Because gravitational force decreases with increasing distance, the force of the Moon's gravity is less on the side of Earth facing away from the Moon than on the side of Earth facing the Moon. The Sun also causes tides, but the Sun's effect on tides is less than that of the Moon. The effect of their combined gravitational forces is to try to squeeze Earth into an ellipse. However, the Earth's crust is rigid and does not easily deform. The water in the ocean flows and piles up to create high tides. The figure provided shows the tidal bulges created by the gravitational forces of the Moon and Sun.

The ocean tides are influenced more by the Moon than by the Sun. Which of the following best explains this statement?

The diagram below shows the Earth, Sun, and Moon system.

From the diagram, which phase of the Moon will result in a neap tide?

Dustin saw the following moon phase in the sky.

What moon phase will he most likely see in about 7 days?

According to the law of universal gravitation, any two objects are attracted to each other. The strength of the gravitational force depends on the masses of the objects and their distance from each other.

Many stars have planets around them. If there were no gravity attracting a planet to its star, the planet's motion would carry it away from the star. However, when this motion is balanced by the gravitational attraction to the star, the planet orbits the star.

Two solar systems each have a planet the same distance from the star. The planets have the same mass, but Planet A orbits a more massive star than Planet B.

Which of the following statements is true about the planets?

The chart below shows the average surface temperature or temperature range for each of the eight planets.

What conclusion can be drawn from this information?

Each of the eight planets in the Solar System follows a different elliptical orbit around the Sun. An ellipse is a type of oval shape. Each planet's orbit is at a different distance from the Sun than the other planets' orbits.

Beginning nearest to the Sun, the order of the planets is: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

Based on this order, which of the following is true of Jupiter?

In the diagram below, the planets' relative distances from the Sun are shown. The sizes of the planets are not drawn to scale.

Which of the following planets most likely has the warmest surface temperature?

Mercury, Venus, and Earth are the three planets closest to the Sun. The force of gravity on the surface of each planet is different. Which of the following places these three planets in order from greatest surface gravity to least?

Inger does the high jump in gym class. Her best jump is at a height of 4 feet 10 inches.

On which planet would Inger not be able to jump as high as 4 feet 10 inches?

Inger does the high jump in gym class. Her best jump is at a height of 4 feet 10 inches.

On which planet would Inger be able to jump higher than 4 feet 10 inches?

Which belief is the basis of Ptolemy's geocentric model of the solar system?

Which of the following correctly describes the heliocentric model of the Solar System?

The inner planets and the outer planets are separated by which of the following?

What is a hypothesis?

Scientific inquiry includes many different activities. Which of the following is a process that is typically performed during a scientific inquiry?

Tera performed multiple experiments to determine the best growing conditions for Azaleas. In one experiment, she tested the effect of using different types of soil. In another experiment, she tested the effect of exposing the plants to varying amounts of light. And, in another experiment, she tested the use of different amounts of fertilizer. Once she completed her experiments, Tera recorded all of her observations before making a conclusion.

This scenario suggests that

Models can be used to obtain information about scientific processes and objects that may be difficult to study in real life. Which of the following scientific processes or objects would best be studied by using a model?

The following chart presents twelve sets of measurements of the pressure vs temperature for Abilene, TX, taken over a period of four days.

Which of the following is a scientific question that this data can answer?

What is wrong with the steps of Corey's experiment?

Nick is conducting a controlled experiment to test whether music helps daisies grow faster. Below are the steps to Nick's experiment:

Which group is the control group in Nick's experiment?

Nick is conducting a controlled experiment to test whether music helps daisies grow faster. Below are the steps to Nick's experiment:

Which group is the experimental group in Nick's experiment?

Your teacher has asked you to perform an experiment to see if the shape of objects, alone, affects the motion of objects. Which of the following would be the best experiment to perform?

Shakita wants to know if the pH of an open can of soda changes over time. To test this, she designs an experiment that will involve the following steps.

1. Open a can of soda and measure the pH.

2. Allow the open soda can to rest undisturbed on a level countertop at room temperature.

3. Measure the pH of the open soda can every day at the same time for ten consecutive days.

What is the outcome variable (dependent variable) in Shakita's experiment?

Raul wants to study how pot size affects the growth of plants. To do this, he intends to purchase three different pots of varying diameter. Then, he will fill each pot with the same amount of soil and plant different kinds of flowers in each pot. Finally, he will place the pots side by side in a sunny location and water each pot daily with the same amount of water.

Will Raul's experimental set-up produce valid results?

Omar wants to determine if the mass of a model rocket affects how long the rocket is able to stay up in the air. To do this, he constructs three identical rockets and then fills two of the rockets with varying amounts of sand to add mass. He then launches the rockets one at a time and times how long they are able to stay airborne.

What is the test variable (independent variable) in Omar's experiment?

Shawn is planning a scientific experiment. He wants to learn whether time of day has an effect on how far the roses in his mother's garden are open. He plans to measure the diameter of each flower on three rosebushes every hour during a week in the spring.

What is the test variable (independent variable) in Shawn's experiment?

Lexi is researching crime rates. She is trying to make a conclusion about whether the crime rate changes with the population in each county in her state.

What is the outcome variable (dependent variable) of her investigation?

Jami is doing an experiment to find out how temperature slows down or speeds up the sprouting of bean seeds. To prepare for the experiment, she plans to put soil into three foam cups and place six seeds in each cup.

When Jami performs the experiment, which of the following should she keep the same for all of the cups of beans?

I. the amount of sunlight

II. the amount of water

III. the temperature

IV. the amount of fertilizer

Jay wants to know how the amount of acidity in rainwater influences the weathering rate of limestone.

To answer his question, Jay performs an experiment in which he soaks identical pieces of limestone in 200 mL of different carbonic acid solutions. The pH of the solutions range from 3.0 to 5.5. After performing his experiment once, he reports his data and draws a conclusion.

What can Jay do to improve the reliability and accuracy of his data?

Darren performed an experiment in which he measured the amount of force that was required to accelerate an object at a rate of 5 m/s2. Then, he repeated his experiment four more times and calculated the average force that was needed.

Why did Darren repeat his experiment?

Scientists often replicate the experiments that other scientists have already performed. That is, they reproduce an experiment by using the same procedure and materials as another investigator.

Why would a scientist want to replicate another scientist's experiment?

Which of the following procedures demonstrates repetition?

What is the difference between replication and repetition?

The scientific theory of plate tectonics states that the Earth's crust is composed of many plates, or slabs of rock. Interactions of these plates have created different landforms, or geologic features. Which of the following statements provides evidence for this theory?

At one time, most people believed that the Universe was static, meaning it did not change. When larger and better telescopes were invented in the early 1900s, however, it was discovered that light from objects in space shifted toward longer wavelengths. Scientists concluded that only an expanding Universe could explain this shift.

Which of the following statements is supported by this example?

Scientific theories are explanations for naturally occurring events or phenomena. Although scientific theories require extensive observations and experimentation, they can change over time as new evidence is discovered.

Scientific laws are principles that are also based on extensive observations and experimentation. Although scientific theories can develop into laws, a theory can only be declared a law if it is proven to be without exception under certain stated conditions.

Which of the following is true regarding scientific theories, laws, and knowledge?

Scientific knowledge can withstand the test of time because