Show:
Nuclear Changes
Half-life
Vocabulary
Radiometric Dating
Types of Radiation
100

This decay increases atomic number by +1? 

Beta Decay, a neutron becomes a proton

100

If 50% remains, how many half-lives have passed? 

1 half-life

100

Define this term. What is the time required for half of a radioactive sample to decay? 

half-life

100

This isotope is used for measuring age of fossils?

carbon-14

100

Which radiation is most penetrating?

Gamma Radiation

200

Alpha decay reduces atomic number by: (include the sign +/-)

-2

200

80g --> 20g represents this many half-lives? 

2 half-lives

200

To become more stable, they release energy or atomic particles. This process is called? 

Radioactive decay

200

This isotope is used for measuring age of rocks?

Uranium-238

200

This type of radiation has no mass and no change? 

Gamma Radiation, it's pure energy

300

Which decay(s) produces a different element? 

Alpha and Beta Decay

300

What percentage of the original sample is left after 2 half-life?

25%

300

In chemistry and physics, the sum of the neutrons and protons is normally referred to as the:

mass number

300

This is why carbon dating doesn't work on rocks?

There are no carbons in rocks since rocks have never been alive. 
300

This radiation can be stopped by paper? 

Alpha radiation

400

Beta Decay changes mass number by:

zero, 0

400

Based on this half-life equation, N = N0 (½) t/t1/2, what does N0 represents? 

Original Amount of Mass
400

The technique used to determine the age of materials like rocks or carbon-based artifacts by measuring the decay rate of radioactive isotopes is called:

Radiometric or radioactive dating.

400

A shorter half-life means it's decaying faster or slow? Explain why. 

A shorter half-life means it's decaying faster since it decays the same amount in less time. It's like running half of a 100 m dash in less time than someone else. 

400

What material is needed to stop gamma radiation?

lead

500

Alpha decay changes mass number by: 

-4, lost 2 protons and 2 neutrons

500

After 3 half-lives from 60g of carbon-14, the remaining mass of carbon-14 is:

7.5 g

500

According to this principle, lower rock layers are older than layers above them.

Superposition

500

Why doesn't carbon dating work beyond 50,000 years?

A half-life of carbon-14 is 5730 years. So 50,000 years is close to 10 half-life. At that point, it's hard to discern what exact percentage of carbon-14 is remaining. The difference between 10 and 11 half-lives is a fraction of a percent.

500

What material is needed to stop beta radiation?

Plastic or aluminium