Radioactivity

In the above decay equation, what are the missing numbers x and y?

• A

• B

• C

• D

Tags

NGSS.HS-PS1-8

The half-life of a substance is

• the amount of substance left after it has decayed

• the time it takes for half of the isotope to decay

• the time it takes for half the mass to have radiated away

• the mass of half of the isotope after decaying

Tags

NGSS.HS-PS1-8

The activity of an isotope is

• the number of particles/rays emitted per second

• the same as the half-life in seconds

• the amount of radiation emitted over the lifespan of the isotope

• the amount of heat generated per second

Tags

NGSS.HS-PS1-8

Which of the above graphs shows how the activity of a sample varies with time?

• A

• B

• C

• D

Tags

NGSS.HS-PS1-8

A sample of 16 g of radioactive substance X has a half-life of 2 hours. What percentage of the sample is left after 6 hours?

• none

• 12.5 %

• 25 %

• 33.3 %

Which of the following half-lives would be most suitable for a medical tracer used in a patient?

• 3 minutes

• 3 hours

• 3 days

• 3 years

What form of radiation should a medical tracer emit?

• alpha

• beta

• gamma

• any of these

Tags

NGSS.HS-PS1-8

The arrows in the diagram below represent radiation passing between electrically charged plates.

 

The arrow marked “2” could represent:

• Gamma radiation

• An alpha particle

• A beta particle

• A proton

Tags

NGSS.HS-PS1-8

Which type of reaction is the atomic number increased but atomic mass unchanged?

• Beta decay

• Fusion

• Alpha decay

• Gamma decay

Tags

NGSS.HS-PS1-8

In alpha decay, the atomic number...

• increases by 2

• decreases by 2

• increases by 4

• decreases by 4

Tags

NGSS.HS-PS1-8