Semester 1 Final ReviewMs. Girard and Mrs. Arevalo

Principles of Env. Sci.Legacy High School

Radioactivity

Radioactivity

The process whereby unstable atomic nuclei break down and emit

radiation

Nuclear Radiation

The transfer of energy by means of electromagnetic

waves.

Half-Life of Radioactive Elements

Half-Life

The time required for half the atoms of a sample of a

radioactive isotope to decay.

Half-Life Calculations

½ Life Mulitplied by

Amount

0 0 400 Atoms

1 ½ 200

2 ½*½ = ¼ 100

3 ¼*½ = ⅛ 50

4 ⅛*½ = 1/16 25

Nuclear Radiation

Alpha Particles

• Are cluster of particles containing two protons and two neutrons

• Travel less than 4 inches in the air

• Absorbed by paper

Beta Particles

• Very high energy electrons emitted when a neutron in the nucleus decays

• Range of about three feet

• Blocked by a thin sheet of lead

Nuclear Radiation

Gamma Rays

•High energy electromagnetic waves that move at the speed of light

•Blocked by a block of lead

1. A performer pulls a tablecloth out from under a set of dinnerware as shown in the picture. What best explains the performer’s success at leaving all the dinnerware on the table?

The inertia of the dinner ware.

2. A car is parked on a hill. What most likely prevents the car from moving down the hill?

There is friction between the tires and the ground.

3. Below is a distance vs. time graph showing the action of a person over time. What statement is the best description of the person’s action?

The person is walking at a constant speed.

4. Below is a velocity vs. time graph showing the movement of a train over time. Use this graph to answer the following question. What statement is the best description of the train’s motion?

The train is not moving in any direction!

5. In what situation is the most work done?

a) Lifting a 50 N box up 2 meters.

b) Lifting a 50 N box up 2 meters and then down 2 meters.

c) Lifting a 75 N box up 1 meter.

d) Lifting a 75 N box up 1 meter and then down 1 meter.

6. A bicycle rider is traveling at a constant speed of 3 m/s. How far will the bicyclist travel in thirty minutes?

Distance = velocity X time

D = vt = 3m/s X 1800 s = 5400 meters (m)

7. If the Earth were twice as massive, then the gravitational force between it and the sun would be

Twice as great

8. The distance between two charges is represented by “d”. What diagram shows the greatest attractive force between the two charged objects?

A.

B.

C.

D.

8. The distance between two charges is represented by “d”. What diagram shows the greatest attractive force between the two charged objects?

A.

B.

C.

D.

9. What statement best explains why an astronaut weighs less on the Moon than they would on Earth?

The moon has less mass so gravitational force is less on the moon.

10. An electrostatic paint sprayer is used to spray paint evenly onto the surface of a car. Before the paint is sprayed, the car body is given a positive charge and the paint droplets are given a negative charge. The paint droplets experience an attractive force as soon as they are released from the sprayer. The paint droplets are originally sprayed at a distance of 30 cm from the car body, as shown below. What changes will cause the largest increase in the attractive force on the paint droplets?

The distance between the paint droplets and the car body is halved

11. In each diagram below, the mass of two objects is labeled. These masses are separated by a radius. Which diagram would produce the greatest gravitational force between the two objects?

Diagram 1

12. Electromagnetic induction is the process by which an electric current is produced by moving a wire in a magnetic field. What device works on the principle of electromagnetic induction?

A generator.

13. A 1500 kg car has an applied forward force of 5000 N and experiences an air resistance of 1250 N. What is the car’s acceleration?

Force = Mass X Acceleration

3750 N = 1500 kg X a

a = 3750 N / 1500 kg

a = 2.5 m/s2

2 Forces:

Net Force = F1 – F2

Net Force = 5000 N – 1250 N

Net Force = 3750 N

14. A cart with a mass of 100 kg accelerates when 10 N is applied. If the mass is doubled, how much force is required to maintain the same acceleration.

Force = Mass X Acceleration

Acceleration = Force / Mass

A = 10N/100kg = 0.1 m/s2

F = (2 * 100kg)(0.1m/s2) = 200kg(0.1m/s2)

F = 20N

15. Electromagnetic waves of various frequencies reach Earth from distant parts of the universe. What inference can be made from this observation?

The waves can travel without medium (Medium: An intervening substance through which something else is transmitted or carried on - http://www.thefreedictionary.com/medium)

16. To locate objects in their environments, bats in flight and porpoises under water both use ultrasound waves with frequencies that are beyond human hearing. These animals produce an ultrasonic wave and then detect echoes from nearby objects.

If a porpoise and a bat both produce ultrasonic waves when they are 16 m from an object, which animal would hear its echo first and why?  

The porpoise would hear its echo first because sound travels faster in water than

in air.

17. What is possible due to longitudinal waves?

Hearing the sound of an airplane is possible due to longitudinal waves.

18. The burning of gasoline is an example of a chemical reaction in which the chemical energy stored in the bonds between the molecules of gasoline is converted into other forms of energy during the burning process.What is the best statement about the role of energy in the burning of gasoline?

Chemical energy is converted into thermal energy which is released.

19. A toy car with initial kinetic energy rolls to a stop along a flat track. Because of friction, some of kinetic energy was transferred to

Thermal Energy

20. What ways are photosynthesis and cellular respiration alike? Both processes

They involve energy transformations.

21. Nuclear fission reactions are

commonly used in nuclear power plants.

22. What type of reactions will release the most energy per kilogram of reactant?

Nuclear Fusion

23. The difference between ionizing and non-ionizing radiation is that ionizing radiation is located in what range of the electromagnetic spectrum?

Ultraviolet and greater frequencies

24. Carbon-14 is used to date artifacts. The half-life of Carbon-14 is about 6,000 years. After 12,000 years, about how much Carbon-14 would remain in a sample?

¼ or a quarter of the sample would remain.

½ -Life = 6,000

1 half-life would be ½ of the sample left

2 half-lives would be ¼ of the sample left

½ X ½ = ¼

25. Use the following table to answer the question. The reason that alpha particles are stopped by paper and have low penetrating ability is due to

A relatively high mass compared to other

radiation.

26. A thermometer is a device that measures

The average kinetic motion

27. A student bends a paperclip rapidly back and forth. When he touches the point where he was bending the paperclip, he finds that its temperature has increased. This indicates that the atoms in that part of the paperclip have increased in

Kinetic Energy

28. Describe how a dam creates electricity?

Gravitational potential energy transfers to kinetic energy which turns a generator.

29. What role do electrical generators or batteries have in circuits?

They are the source of potential energy in a circuit.

30. What function does a circuit serve in your home?

It provides a complete path through which electrical energy can flow.

31. At standard pressure and room temperature, water is a liquid and carbon dioxide is a gas. Water and carbon dioxide exist in different states because

The forces are greater between water molecules.

32. Describe the differences between solids and liquids?

Solids have a definite volume and shape, but

liquids only have a definite volume

33. What happens to the particles of a gas as it changes phase into a liquid?

They slow down and become closer because energy is being removed

34. What group of elements would be expected to have similar properties?

Oxygen, sulfur & magnesium

35. The figure to the right shows part of the periodic table. What is an accurate comparison of the atomic number and mass of copper (Cu) and gold (Au)?

Gold (Au) has both a greater atomic number and a greater

atomic mass than copper (Cu)

Carbon6

C12.011

Silver47

Ag107.87

Gold79

Au196.97

36. Which of the following elements can form an anion that contains 54 electrons, 74 neutrons, and 53 protons?

37. Describe the physical separation of the components of a mixture?

When salt is isolated from seawater through evaporation

38. Physical properties of a mixture

Vary depending upon its components

39. Concrete is composed of Portland cement, rocks, sand, and water. What best describes concrete?

Heterogeneous mixture

40. Observe the diagrams on the right showing ionic and covalent bonding. What statement correctly describes the models ?

Model II shows ionic bonding because 1

electron is transferred to another atom.

41. Analyze the model of an atom.

I. The electrons in the outer most shell perform

bonding

42. What is an example of alkali metals forming ionic bonds with nonmetals?

Potassium (K) can form ionic bonds with Chlorine (Cl)

43. What factor will most likely increase the rate of a chemical reaction.

Grinding a solid reactant into powder

44. Sugar in our cells reacts very quickly with oxygen. The same sugar will react very slowly with the oxygen in air. The reason for this difference is because

Cells contain catalysts to speed the reaction

45. What statement best describes the role of energy in all chemical reactions? All chemical reactions

Either release or absorb energy

46. According to the Law of Conservation of Mass, the number of iron (Fe) atoms needed to complete the following reaction is

_4_Fe + 3O2→2Fe2O3

47. The chemical equation below represents the chemical reaction between the elements hydrogen and oxygen when the compound

water is formed.2H2+ O2→ 2H2O

 This equation supports the law of

conservation of mass because

The mass of hydrogen and oxygen in the reactants is equal to the mass of the water

in the product

48. Deuterium (H ) and protium(H ) are two isotopes of hydrogen. What statement best

compares a deuterium atom to a protium atom?

 The deuterium atom has

More particles in the nucleus

49. The mass number of an element is the total number of protons and neutrons located in the nucleus. If carbon has an atomic number of 6 and a mass number of 12, how many neutrons does it contain?

6 Neutrons

Atomic Mass = Neutrons + Protons

Neutrons = Atomic Mass - Protons

50. What best describes a particle that contains 36 electrons, 49 neutrons, and 38 protons?

A cation with a charge of 2+

51. An oxygen atom has 8 protons, 8 neutrons and 8 electrons. If the oxygen atom gains two electrons to form an oxygen ion what will be the magnitude and sign of the charge?

2-

Electrons = negative

Protons = positive

Neutrons = No Charge

52. What is the primary energy source behind the water cycle?

Sun’s electromagnetic radiation

53. Use the diagram to answer the following question. What is not a contributing factor to the uneven warming of Earth’s surface?

The sun is farther from the earth during winter

54. Ozone helps prevent ultraviolet (UV) radiation from reaching Earth’s surface by

Absorbing UV radiation into its molecular structure

55. Cyanobacteria first appeared in Earth’s oceans over 2 billion years ago and were extremely abundant by 545 million years ago. Cyanobacteria affected Earth’s atmosphere by

Gradually adding to the amount of oxygen in the atmosphere

56. A graph of atmospheric carbon dioxide concentration over time is shown below. Scientists are investigating the cause of the significant change in the trend of atmospheric carbon dioxide concentration since the 1800s.What provides the best explanation for the increase?

The use of fossil fuels by humans

57. The two most abundant greenhouse gases in Earth’s atmosphere are

Water Vapor (H2O) & Carbon Dioxide (CO2)

58. Greenhouse gases help keep Earth at a habitable temperature by

Retaining some of the sun’s energy in our lower atmosphere

59. Over the next century, the temperature in the Great Basin Desert is expected to increase anywhere from 2 to 5 degrees Celsius due to global climate change. What best explains how the movement of heat will likely be affected in the Great Basin Desert due to global climate change?

Radiation will transfer the same amount of heat from the sun to the Earth’s surface and

more heat will be moved around in the atmosphere via convection

60. The diagram represents an experiment on different types of soil. The thermometers are measuring the temperature of the center of the soil samples. What is a cause of the measured difference in the temperature of the two soils?

Conduction within different soil types

61. Use the diagram to answer the following question. Analyzing the input and output of solar radiation reveals that

More solar radiation is absorbed by Earth’s

surface than is reflected

62. Surface currents are created

By frictional drag of the wind against the surface of the ocean waters

63. A hurricane in the Northern Hemisphere had a northward direction of motion. Due to the Coriolis Effect, the hurricane ended up

East of the direction it was travelling

Any Questions