A factory uses two kinds of small, low radioactivity sources in the manufacture of smoke alarms. Workers are given these health and safety instructions: Type 1 sources Always wear latex rubber gloves when handling Type 1 radioactive sources. Do not eat or drink when handling Type 1 radioactive sources. Type 2 sources Always wear latex rubber gloves and use tongs when handling Type 2 radioactive sources. Do not eat or drink when handling Type 2 radioactive sources. Always hold Type 2 sources at least 10 cm away from the body. State which radioactive sources most likely correspond to Type-1 and Type-2?

Type-1 sources The Type-1 sources most likely correspond to alpha particles, as alpha particles are positively charged and made up of two protons and two neutrons from the atom’s nucleus. Even though alpha particles are very energetic, they are so heavy that they use up their energy over short distances and are unable to travel very far from the atom. The health effect from exposure to alpha particles depends greatly on how a person is exposed. Alpha particles lack the energy to penetrate even the outer layer of skin, so exposure to the outside of the body is not a major concern. Inside the body, however, they can be very harmful. Type-2 sources The Type-2 sources most likely correspond to beta particles, as beta particles are small, fast-moving particles with a negative electrical charge that are emitted from an atom’s nucleus during radioactive decay. Beta particles are more penetrating than alpha particles, but are less damaging to living tissue and DNA because the ionizations they produce are more widely spaced. They travel farther in air than alpha particles, but can be stopped by a layer of clothing or by a thin layer of a substance such as aluminium.

With reference to information in the table, outline the reason for each of the health and safety instructions. Name What is it? Electric charge Mass(atomic mass unit) alpha 2 protons+2 neutrons Positive 4 beta High energy electron Negative 1/1837 gamma Part of the electromagnetic spectrum None 0

Alpha particles: The health effect from exposure to alpha particles depends greatly on how a person is exposed. Alpha particles lack the energy 1 to penetrate even the outer layer of skin, so exposure to the outside of the body is not a major concern. The way these large, heavy particles cause damage makes them more dangerous than other types of radiation. The ionizations they cause are very close together - they can release all their energy in a few cells. This results in more severe damage to cells and DNA. Beta particles: Beta particles are more penetrating than alpha particles, but are less damaging to living tissue and DNA because the ionizations they produce are more widely spaced. They travel farther in air than alpha particles, but can be stopped by a layer of clothing or by a thin layer of a substance such as aluminium. Some beta particles are capable of penetrating the skin and causing damage such as skin burns. Gamma particles: Gamma rays are a radiation hazard for the entire body. They can easily penetrate barriers that can stop alpha and beta particles, such as skin and clothing. Gamma rays have so much penetrating power that several inches of a dense material like lead, or even a few feet of concrete may be required to stop them. Gamma rays can pass completely through the human body; as they pass through, they can cause ionizations 2 that d

E M B I B E

MYP By Concept 4&5 Physics>Chapter 11 - What's in an Atom?>SOME SUMMATIVE PROBLEMS TO TRY>Q 2

HARD

MYP:4-5

IMPORTANT

Earn 100

Carbon-14 undergoes beta decay. Write a beta decay equation for carbon-14.

Important Questions on What's in an Atom?

MEDIUM

MYP:4-5

IMPORTANT

MYP By Concept 4&5 Physics>Chapter 11 - What's in an Atom?>CONSIDER AND ANSWER THESE QUESTIONS:>Q 1

What is inside an atom?

MEDIUM

MYP:4-5

IMPORTANT

MYP By Concept 4&5 Physics>Chapter 11 - What's in an Atom?>CONSIDER AND ANSWER THESE QUESTIONS:>Q 4

How can we harness energy inside an atom?

HARD

MYP:4-5

IMPORTANT

MYP By Concept 4&5 Physics>Chapter 11 - What's in an Atom?>CONSIDER AND ANSWER THESE QUESTIONS:>Q 3

Is nuclear power the answer to our sustainable energy needs?

HARD

MYP:4-5

IMPORTANT

MYP By Concept 4&5 Physics>Chapter 11 - What's in an Atom?>SOME SUMMATIVE PROBLEMS TO TRY>Q 1

A factory uses two kinds of small, low radioactivity sources in the manufacture of smoke alarms. Workers are given these health and safety instructions:
Type 1 sources

Always wear latex rubber gloves when handling
Type 1 radioactive sources.
Do not eat or drink when handling Type 1 radioactive sources.

Type 2 sources

Always wear latex rubber gloves and use tongs when handling Type 2 radioactive sources.
Do not eat or drink when handling Type 2 radioactive sources.
Always hold Type 2 sources at least 10 cm away from the body.

State which radioactive sources most likely correspond to Type-1 and Type-2?

HARD

MYP:4-5

IMPORTANT

MYP By Concept 4&5 Physics>Chapter 11 - What's in an Atom?>SOME SUMMATIVE PROBLEMS TO TRY>Q 1

With reference to information in the table, outline the reason for each of the health and safety instructions.

Name	What is it?	Electric charge	Mass(atomic mass unit)
alpha	2 protons+2 neutrons	Positive	4
beta	High energy electron	Negative	1/1837
gamma	Part of the electromagnetic spectrum	None	0

HARD

MYP:4-5

IMPORTANT

MYP By Concept 4&5 Physics>Chapter 11 - What's in an Atom?>SOME SUMMATIVE PROBLEMS TO TRY>Q 2

Carbon-14 undergoes beta decay. Write a beta decay equation for carbon-14.

HARD

MYP:4-5

IMPORTANT

MYP By Concept 4&5 Physics>Chapter 11 - What's in an Atom?>SOME SUMMATIVE PROBLEMS TO TRY>Q 2

Question Image

Use the graph to find the half life of carbon-14 in years.

MEDIUM

MYP:4-5

IMPORTANT

MYP By Concept 4&5 Physics>Chapter 11 - What's in an Atom?>SOME SUMMATIVE PROBLEMS TO TRY>Q 3

The scientist carrying out experiment notices that the curve of beta track is always much sharper than that of the alpha particle. Explain why this might be?

Learn and Prepare for any exam you want !

|

|

|

|

|

|

|

|