In physical science lab, Ben and Jerry added small pieces of magnesium to hydrochloric acid. They noticed that bubbles formed, the test tube got hot, and the magnesium disappeared. What is a sign that a chemical reaction has taken place in this experiment?

The table shows the density and volume of four liquid samples. The four liquids do not mix with each other. What is the order in which the layers will be formed, from top to bottom, if the four liquids are poured into a beaker and allowed to settle?

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If water with the mass of 15.0 grams is heated into water vapor in a closed system such as a closed glass jar, what is the mass of the gas after the water completely vaporizes?

A __________ has distinct properties and composition that never vary.

I. O₂ is chemically bonded together.

II. O₂ is divisible.

III. Oxygen is a nonmetal.

IV. The natural state of oxygen is as a diatomic gas.

Which conclusion can be drawn from these statements about O₂?

When Kay added 30 g of hydrochloric acid (HCl) to 65 g of Zn, bubbles appeared and a white precipitate, zinc chloride (ZnCl2) was produced. She found that the mass of the zinc chloride was 63 g. Since the Law of Conservation of Matter stated that matter can't be created or destroyed, she was puzzled about the difference in mass. What is the best explanation for the missing 2 g?

Consider the phase change taking place in the picture. You could use ALL BUT ONE statement to describe what is happening here. That is:

A certain substance is a solid at 15°C. Sarah heated a sample of the solid substance in a beaker using a Bunsen burner during science class. She and her partner recorded the temperature at one-minute intervals. Their data is recorded in the table below. Based on the girls' data, when was the kinetic energy of the substance the greatest?

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Muscles convert chemical energy into

Two iron rods are placed horizontally, touching end-to-end. One end of one rod is heated. After some time, the other rod also feels warm to touch. How did the heat travel from the heated rod to the one that was not heated?

Maria’s father started a fire in the fireplace. He crumpled some paper, lit a match, and soon the logs in the fireplace were burning. In this case, the stored chemical energy in the logs was changed into

Bruce left some butter out in his kitchen. Bright sunlight came in through the window and melted the butter. Heat energy from the sun is called

Which point on the roller coaster's path represents the maximum potential energy?

A drawn bow possesses mechanical energy in the form of _______________. After the arrow is released, the energy is transformed into _________________.

A skateboarder heads down a smooth, steep course. What graph illustrates the change in kinetic and potential energy during this process?

In this scenario a battery is used to supply chemical potential energy. The potential energy is transformed and produces kinetic energy. The battery causes a fan to spin and that kinetic energy can also be described as mechanical energy. Check out the values for each: 100 J potential energy results in 75 J of kinetic energy. What conclusion can be drawn from the energy transformation diagram?

You are sitting in a car that isn't moving; suddenly, the car quickly accelerates. Your body seems to be pushed back against the seat. Which word best explains why your body seemed to be pushed backward against the seat?

How many accelerations (positive or negative) are shown in this graph?

Mutt and Jeff are running along a path each pushing a cart loaded with rocks. If Mutt's wagon has a mass two times greater than Jeff's and they want to stay together, arriving at their destination at the same time, what must happen?

Your teacher was given an apple by a student trying to get on her good side. It sits on her desk the whole year, not moving.

You know that, if the apple were to roll off the desk, it would fall to the ground. So what is keeping the apple motionless on the desk?

According to the diagram, the block should be moving in which direction?

Consider the car driving around a circular track. Once started, the driver maintains a speed of 45 m/h. Compare the driver's velocity with his acceleration in this case.

Which characteristic accounts for the fact that red lights are used in dark rooms and DO NOT expose negatives during developing?

AM Radio Waves

Ultraviolet Light

X Rays

Visible Light

What is true for ALL of the examples of electromagnetic waves?

When light enters a pair of glasses, it ______________ when it hits the glass.

The space shuttle is located exactly half way between the earth and the moon. Which statement is true regarding the gravitational pull on the shuttle?

You rub a balloon on your head and it becomes negatively charged. The balloon will be MOST attracted to

Why does light refract when it encounters the glass in a lens?

Mike wants to negatively charge a small rubber ball. Which of these methods would successfully charge the ball?

Which choice BEST represents the sound waves from a soft low-pitched train rumble that suddenly shifts to a loud, high-pitched squeal of brakes?

Which diagram BEST represents the light waves of a bright red brake light on the left side to a dim violet night light on the right side?

This graph is accurate because

The wave pictured represents a sound wave. Which label along the wave represents a sound with the LOWEST intensity?

What happens when light strikes a translucent object?

How does a concave lens differ from a convex lens?

Lucy tells her classmates that while she was at the lake, she realized that when she dove underwater, she couldn't hear anything. Lucy thinks this is because sound can not pass from the air into the water. Is she right?

This picture shows a standard electric field created by a point charge.

This electric field will influence

In a _____________ wave, vibrations are perpendicular to the direction of the wave motion. In a _____________ wave, vibrations are parallel to the direction of the wave motion.

__________ transmit signals that carry pictures, data, music and conversations invisibly over long distances and have been the basis for almost all non-written communication and most wireless technologies used by humans today.

Based on the table, what might be a reasonable conclusion?

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An electromagnet is created using a battery, an insulated copper wire and an iron nail. The wire is wrapped around the nail 20 times and attached to the battery. Which pair of changes will definitely increase the strength of the electromagnet?

A student looks at ocean waves coming into the beach. An ocean wave with more energy will

The attracting and repelling forces of magnets are used in countless objects, from refrigerator doors to maglev trains. Refrigerator doors use the attraction of magnets to stay closed, while maglev trains use magnetic repulsion to hover above rails. The center magnet in the picture is hovering between two magnets, making it appear to float. Which best explains how the center magnet is able to hover between two other magnets?