Physical science Exam Review

Which model best represents a change that results from adding thermal energy to a substance in a jar?

B

Water can undergo a change of state from liquid to _______ by decreasing the air pressure on its surface.

Gas

In general, metals are ____ since they are composed of individual atoms or small molecules.

Good conductors of heat

The model shown represents one molecule of hydrazine, a chemical in rocket fuel. The black spheres represent nitrogen atoms, and the white spheres represent hydrogen atoms. Based on the model, what is the atomic composition of hydrazine? The black spheres represent nitrogen atoms, and the white spheres represent hydrogen atoms. Based on the model, what is the atomic composition of hydrazine?

2 atoms of nitrogen and 4 atoms of hydrogen

Two students are working together to build two models. Both models will represent the molecular structure of sodium bicarbonate, NaHCO3, commonly known as baking soda. The students are using toothpicks to represent bonds and jelly beans to represent atoms. Red jelly beans represent sodium atoms (Na), white jelly beans represent hydrogen atoms (H), black jelly beans represent carbon atoms (C), and blue jelly beans represent oxygen atoms (O) Identify the number of each color of jelly bean needed to make both models of NaHCO3. Explain your reasoning

4 jelly beans because Each of the letters equal one jelly bean

At which temperature are the particles in a pencil moving the fastest?

50 degrees C

Companies often use an insulated box to ship items that must maintain a certain temperature. The interior walls of an insulated box are typically lined with a material that reduces the transfer of heat out of the box. Describe a plan for an investigation to determine which is better at reducing heat transfer: a box insulated with foil or a box insulated with foam. In your answer, be sure to include materials used in the investigation.

A box with foam is a thermal insulator, it reduces heat.

Give one example each of a thermal conductor and a thermal insulator.

A thermal conductor is cooper and an insulator is wood.

The table shows models of four molecules and describes the atomic composition of each molecule. a. Based on the information on the table, describe the atomic composition of methane. Use specific information from the table to explain your reasoning. b. The atomic composition of carbon monoxide is one carbon atom and one oxygen atom. Using the models in the table as examples, describe a model of carbon monoxide.

A. 4 hydrogen atoms and 1 carbon atom. I got my answer by looking at the chart and comparing atoms B. The atoms would be connected. It would show one carbon atom and one oxygen atom. The colors would be black and grey.

Kim places 10 grams of ice at 0°C in a beaker that contains 80 grams of water at 20°C. When the ice melts completely, she measures the temperature of the water, which is at 9°C. a. Describe two ways that Kim could change the activity to get a colder final temperature. b. Based on your answer to part (a), explain how the kinetic energy of this ice and water system will change.

A. Kim could do the expermiment at a colder area or freeze the water B. The kinetic energy will increase.

Molly is given two identical 300-gram cups that have the same volume of hot chocolate in each. Each cup of hot chocolate is at a different temperature. Molly is also given 10 ice cubes that each have the same mass and are at the same temperature. a. List the steps of an investigation that uses only the materials described above to show which cup of hot chocolate is hotter. b. Explain why it is important that the masses of the materials in the investigation be the same.

A. Molly cold put 10 ice cubes in the hot choclatte and set a 2 minet timmer, when the timer is done she could see what cup is hotter. B. If the masses were diffrent that could casue on the the cups to cool faster

A student researches the use of a pressure cooker to cook foods quickly at temperatures above the normal boiling point of water. (a.) How could you use a particle model to describe why the pressure in a sealed pressure cooker increases as the water is heated. b. What effect does the higher pressure have on the boiling point of water? Explain your reasoning.

A. Particles of water move faster as they are heated. Some of the water changes from liquid to gas. The gas particles move faster as they are heated. They collide with the walls of the pressure cooker harder and more often, which increases the pressure B. The higher pressure causes the boiling point of water to increase. Water molecules need more energy to escape the liquid when the pressure above the liquid is greater

Bethany observes a white crystal that is cube shaped under a microscope. Based on this observation, Bethany thinks the crystal could be sodium chloride, or table salt. Because the crystal has an extended structure, she knows that sodium chloride is not a molecule. Bethany uses gray and white spheres, representing the atoms in sodium chloride, to make a model of the crystal's most likely structure, as shown. a. Provide two reasons why the model accurately represents sodium chloride. Support your reasons with evidence from the model. b. Predict whether the melting point should be high or low based on the model.

A. Sodium chloride is not a molecule and it has a extended structure. B. High melting point

A student half fills a jar with rice and tightens the jar's lid. The student wants to use the jar of rice to model particle motion of a substance in any state of matter. a. Describe how the student can use the jar of rice to model particle motion of a substance in each state of matter: solid, liquid, and gas. b. Compare the amount of kinetic energy of particles in each state of matter.

A. The student can fill the jar with rice all the way to demonstrate a solid. To show a gas the student could add less rice to th jar and distance the rice. The student could fill the rice half way for the liqued. B. Gas has a lot of kentic energy. Solids have a low kenitc enery and liqueds have more kenetic energy than solids

Wanda wants to compare how different substances absorb heat. She has samples of iron, granite, and pure water. Each sample has a mass of 1 gram. (a.) Describe an investigation where Wanda can compare how each substance absorbs heat. Be sure to include the tools used in the investigation Wanda claims that iron and granite absorb heat faster than water does. b. Describe results of the investigation that would support Wanda's claim.

A. wanda can put all three under a heat sourse amd put a timer on. Then feel which thing is the warmest once done. B. The things would be warmer compared to water

Model x and model y both represent particles of the same substance. a. Identify the states of matter represented by Model X and Model Y. Support your answers with evidence from the models. b. Describe a third model that would represent the particles of the same substance in a state of matter not represented by Model X or Model Y. Explain your reasoning.

A.) Model X is a solid because the particles are close together in a tight pattern. Model Y is a Liquid because the particles are not to far apart or close together. B. The Third model would be a gas because that is only Last state of matter left.

Bars of different metals are all heated to 100°c to determine how their volume and length would be affected which statement describes the most likely outcome of this experiment

All of the volumes change and so do their lengths.

Which properties describe elements that are nonmetal gases? Select all that apply.

Composed of an extended structure, low melting point, weak attraction between particles

When a liquid boils, its particles get ____. This may be due to the ____ in pressure.

Further apart; decrease

Substances are either elements or mixtures

false

Most materials ____ when they are heated

Expand

Air is a good conductor of heat.

False

Matter is made up of motionless particles. _______________

False

Radiation transfers energy by moving matter.

False

When a substance is cooled it usually expands.

False

A substance has an extended structure composed of two different elements. The elements are a metal and a nonmetal. Which property would this substance most likely have?

Has night melting point

Aspartame is an artificial sweetener; its formula is C13H16N2O5. What element in the formula has the most number of atoms?

Hydrogen

Juana is creating a lab simulation about the movement of the particles in a nonmetal gas. The user can change the pressure in the gas' temperature and see the effect of the change in the gas' volume. What changes should Juana program to cause the decrease in the gas' volume?

Increase in pressure Decrease in temperature

Vaporization occurs when a ______changes into a _____

Liquid, gas

Adding thermal energy to a cup of water can cause particles to do which of the following? Select all that apply.

Move slower, get closer together

The forces of attraction between the particles of a matter sample are strong and draw particles together, keeping them in their place. This is an example _____.

Of the solid state of matter

Why does oil not dissolve in water?

Oil is made of nonpolar molecules, and water is made of polar molecules.

Kenitic energy is the ______ of motion

Temperature

particles in a material is ________, while the result of the motion of all the particles, and the distance and attractions between those particles in the system is _______ energy.

Temperature, thermal

Jocelyn used a balloon to make a model of gas particles. She measured the balloon's diameter at room temperature. Then, she placed the balloon in a freezer. An hour later, she removed the balloon from the freezer and measured the diameter immediately after. Jocelyn made these drawings to show the balloon's diameter at room temperature and immediately after removing it from the freezer. The dotted line represents the size of the balloon before placing it in the freezer. Then, Jocelyn placed the balloon in a tub of heated water that is warmer than the room temperature. Which is the best prediction of what may happen?

The balloon expands to a diameter over 10 cm because the gas particles move faster.

Explain why different substances are solids, liquids, or gases at room temperature.

The substances depend on the temperature and pressure

Changes in temperature, pressure and volume affect the behavior of gases more than they affect solids and liquids

True

Compared to water, most metals have low specific heats.

True

Temperature is the measure of the average kinetic energy of a substance.

True

The sum of the potential energy and the kinetic energy of an object is its thermal energy

True

Thermal energy can increase even if the average kinetic energy is constant.

True

Marco put a pot of water on to boil eggs. Half an hour later, he returned to find the pot dry. This is an example of ______.

Vaporation

An oven with a convection setting has a fan and vent system that keeps air moving around inside of the oven. Conventional ovens do not have this type of system. Joelle claims that convection ovens cook food more quickly and evenly.

a conventional oven cooks food with out air ciculation but a convection oven has a fan that allowes air to flow around.

Consider an iceberg and a hot cup of tea. Compare the two in terms of temperature and thermal energy

an iceberg has a lower tempeture amd has more thermal energy than tea.

How are pressure and volume related at a constant temperature

as volume increases, pressure decreases

Temperature is a measure of ____ of the particles in an object.

average kinetic energy

The temperature at which a liquid becomes a gas is the ____ point.

boiling

Which is a property of metals as a result of their extended structures of atoms?

can be hammered into sheets

When a liquid freezes, its particles get ____. This could result from the pressure ____.

closer together, increasing

During a hot shower, water vapor fogs up the cooler mirror when it turns to water. This is an example of

condensation

The change in state from a gas to a liquid is called

condensation

Hot water is poured into a mug and the mug gets hot. This is an example of which type of energy transfer?

conduction

You grab a bottle of water out of the refrigerator. Your hand gets cold because of which of the following?

conduction

A material whose particle composition allows heat and electricity to pass through it easily are described as having a high ____.

conductivity

A good ________ transfers heat easily.

conductor

When a pot of water is put on a stove, the water at the surface gets hot primarily by _______.

convection

Which type of energy transfer is responsible for the movement of magma in Earth's interior?

convection

Each of the following is a state of matter EXCEPT ____.

density

Describe an experiment to test the effects of temperature on diffusion. Identify which variables you would control and which variable you would vary. Include a definition of diffusion.

diffusion is the movement of a substance from an area of high concentration to an area of low concentration.

While a substance is boiling, its temperature ______.

does not change

When two materials that are in contact have the same temperature, the materials are said to be in thermal

equilibrium

A liquid thermometer works because liquid ____ when warmed.

expands

In which state of matter there are very weak attractions between particles?

gas

The ocean is cold even in summer because water _________.

has high specific heat

Hot-air balloons typically fly in the early morning or late afternoon. Briefly explain why.

hot air ballons fly in the early morning or late afternoon beacause those are the time periods when the tempeture is lower and the ballon can fly better.

As long as the temperature does not change, as the volume _____ the pressure _____.

increases, decreases

When temperature increases, average _____ increases.

kinetic energy

Kinetic energy is the energy of

motion

Adding thermal energy to a cup of water may cause the particles to __________

move faster

The molecules in water are farther apart than the molecules in ice. Therefore, the molecules in water have more _________ than the molecules in ice.

potential energy

The amount of force that is exerted on a balloon by the gas inside the balloon is _____.

pressure

The measurement of force per unit area is called

pressure

Which type of energy transfer allows the Sun to warm Earth?

radiation

Particle motion in ice is ________ than particle motion in water.

slower

What two states of matter are pictured in the image below?

solid to liquid

You can separate the particles that make up sugar from the particles that make up sand because sugar are ____ and sand are not.

soluble in water

The amount of heat required to raise the temperature of 1 kg of a substance by 1°C is its

specific heat

The evaporation of water is an example of a change in

state

When a substance is heated, the particles gain energy and move apart, increasing the volume. The mass of the substance being heated _______.

stays the same

The state of matter of a material depends on it's

temperature

When ice melts from a pond in the spring, what happens to the air above it? Why?

the air above the ice becomes cooled and becomes water vapor, this is beacuse the tempature of the water in the spring becomes warmer.

Most highway bridges are built with expansion joints that can move back and forth. What is the reason for this?

the materials that make up the bridge will expand and contract with changes in tempature

A change in the state of matter is caused if enough _____ is added to or removed from an object.

thermal energy

Snow melts after a snowstorm because of the addition of _____.

thermal energy

The combined total of the kinetic and potential energy in a material is called _______.

thermal energy

The sum of all the potential energy and kinetic energy of an object equals its _____.

thermal energy

When water is heated on a stove, which kind of energy is transferred from the element to the water?

thermal energy

change in the state of matter occurs if enough _____ is added or removed from an object.

thermal energy

A hot iron is turned off and cools down to room temperature. The iron cools because ________.

thermal energy is transferred from the warm iron to the cooler room

Marco put a pot of water on to boil eggs. After a few minutes, all the water was gone. This is an example of _____.

vaporization

As the space in a container gets smaller, the _____ decreases.

volume

In a gas which quantities relate n such a way that when one increases, the other one decreases

volume and pressure

Heat always moves from _______ objects to _______objects.

warmer, cooler

Which of the following would be modeled by small particles made up of atoms of two kinds of elements?

water

A student jumped in the ocean on a hot summer day and was surprised that the water was very cold. Use your knowledge of specific heat to explain this.

water has a high specific heat so it stays cool on a hot summer day.

Why would wearing several layers of clothing keep you warmer than wearing one heavy sweater?

wearing multiple layers is warmer because the warm air is trapped between the layers, therfore acting as an insulator

Explain how heat is transferred between a hot and a cold object by conduction.

when an object is a good conductor heat can be easily transfered through it.

Explain briefly why running hot water over the metal lid of a jar can make it easier to open.

when you run hot water under a jar the pressure losens