Half Life OALH

Do Now

1

What happens to the mass number when an alpha particle is released?

Mass number decreases by 4

Mass number increases by 4

1

What happens to the atomic number when an alpha particle is released?

Atomic number decreases by 2

Atomic number increases by 2

1

What happens to the atomic number and the mass number when a beta particle is released?

Mass number stays the same, atomic number stays the same

Mass number increases by 1, atomic number stays the same

Mass number stays the same, atomic number increases by 1

1

Define the dependent variable

The variable you keep the same

The variable you measure

The variable you change

1

Give this number to 3 significant figures: 3.7365

3.7300

3.73

3.74

1

Give an example showing that gamma radiation has more penetrating power than alpha radiation

Key Knowledge - LCWC

1

How is the nature of radioactive decay described?

1

What is the half-life of a radioactive isotope?

1

What happens to the half-life of a particular isotope as more and more nuclei decay?

1

How is the nature of radioactive decay described?

1

What is the half-life of a radioactive isotope?

1

What happens to the half-life of a particular isotope as more and more nuclei decay?

Recall Quiz

1

1)Give two definitions of the half life of a radioactive isotope

The time it takes for the number of nuclei in a sample to half

The time it takes for half the sample to disappear

The time it takes for the count rate from a sample to half

The time it takes for the atom to shrink by half

1

2)What two words are used to describe the nature of radioactive decay?

1

3) How does the half-life for a particular isotope change over time?

I Do

1

I do: Use the graph to calculate the half life - we will do this together as part of the lesson.

We Do

1

We do: Use the graph to calculate the half life - we will do this together as part of the lesson.

You Do

1

You do: 1. Use the graph to calculate the half life

1

You do: 2. Use the graph to calculate the half life

2nd I Do

1

I do: Use the table to calculate the half life - we will do this together as part of the lesson

2nd We Do

1

We do: Use the table to calculate the half life - we will do this together as part of the lesson

2nd You Do

1

You do: Use the table to calculate the half life

3rd I Do

1

I do: Calculate the half life of an isotope if its activity falls from 8000 counts per second to 500 counts per second after 10 minutes - we will do this together in class

3rd We Do

1

We do: Calculate the half-life of an isotope if its activity falls from 120 counts per minute to 30 counts per minute after 20 hours - we will do this together in class

3rd You Do

1

You do: 1. Calculate the half-life of an isotope if its activity falls from 6000 counts per second to 750 counts per second after 6 hours

1

You do: 2. What is half-life of a 500g radioactive sample that decays to 62.5g is 24 hours?

Plenary

1

1)Give two definitions of the half life of a radioactive isotope

The time it takes for the number of nuclei in a sample to half

The time it takes for the atom to shrink by half

The time it takes for the count rate from a sample to half

The time it takes for half the sample to disappear

1

Half Life OALH

What happens to the mass number when an alpha particle is released?

What happens to the atomic number when an alpha particle is released?

What happens to the atomic number and the mass number when a beta particle is released?

Define the dependent variable

Give this number to 3 significant figures: 3.7365

Give an example showing that gamma radiation has more penetrating power than alpha radiation

How is the nature of radioactive decay described?

What is the half-life of a radioactive isotope?

What happens to the half-life of a particular isotope as more and more nuclei decay?

How is the nature of radioactive decay described?

What is the half-life of a radioactive isotope?

What happens to the half-life of a particular isotope as more and more nuclei decay?

1)Give two definitions of the half life of a radioactive isotope

2)What two words are used to describe the nature of radioactive decay?

3) How does the half-life for a particular isotope change over time?

I do: Use the graph to calculate the half life - we will do this together as part of the lesson.

We do: Use the graph to calculate the half life - we will do this together as part of the lesson.

You do: 1. Use the graph to calculate the half life

You do: 2. Use the graph to calculate the half life

I do: Use the table to calculate the half life - we will do this together as part of the lesson

We do: Use the table to calculate the half life - we will do this together as part of the lesson

You do: Use the table to calculate the half life

I do: Calculate the half life of an isotope if its activity falls from 8000 counts per second to 500 counts per second after 10 minutes - we will do this together in class

We do: Calculate the half-life of an isotope if its activity falls from 120 counts per minute to 30 counts per minute after 20 hours - we will do this together in class

You do: 1. Calculate the half-life of an isotope if its activity falls from 6000 counts per second to 750 counts per second after 6 hours

You do: 2. What is half-life of a 500g radioactive sample that decays to 62.5g is 24 hours?

1)Give two definitions of the half life of a radioactive isotope

2.Sketch a graph showing radioactive decay

What happens to the mass number when an alpha particle is released?

What happens to the atomic number when an alpha particle is released?

What happens to the atomic number and the mass number when a beta particle is released?

Define the dependent variable

Give this number to 3 significant figures: 3.7365

Give an example showing that gamma radiation has more penetrating power than alpha radiation

How is the nature of radioactive decay described?

What is the half-life of a radioactive isotope?

What happens to the half-life of a particular isotope as more and more nuclei decay?

How is the nature of radioactive decay described?

What is the half-life of a radioactive isotope?

What happens to the half-life of a particular isotope as more and more nuclei decay?

1)Give two definitions of the half life of a radioactive isotope

2)What two words are used to describe the nature of radioactive decay?

3) How does the half-life for a particular isotope change over time?

I do: Use the graph to calculate the half life - we will do this together as part of the lesson.

We do: Use the graph to calculate the half life - we will do this together as part of the lesson.

You do: 1. Use the graph to calculate the half life

You do: 2. Use the graph to calculate the half life

I do: Use the table to calculate the half life - we will do this together as part of the lesson

We do: Use the table to calculate the half life - we will do this together as part of the lesson

You do: Use the table to calculate the half life

I do: Calculate the half life of an isotope if its activity falls from 8000 counts per second to 500 counts per second after 10 minutes - we will do this together in class

We do: Calculate the half-life of an isotope if its activity falls from 120 counts per minute to 30 counts per minute after 20 hours - we will do this together in class

You do: 1. Calculate the half-life of an isotope if its activity falls from 6000 counts per second to 750 counts per second after 6 hours

You do: 2. What is half-life of a 500g radioactive sample that decays to 62.5g is 24 hours?

1)Give two definitions of the half life of a radioactive isotope

2.Sketch a graph showing radioactive decay