Nuclear Decay & Artificial Transmutation Quiz

Question 1

Which best describes nuclear decay rate?

Accepted Answer

how fast nuclear changes happen in a radioactive substance

Question 2

Which statement describes a radioisotope's half-life?

Accepted Answer

the time it takes for 50% of a sample to decay, the time it takes for 1/2 of a sample to decay

Question 3

What happens to the other half of a radioisotope's atoms after one half-life?

Accepted Answer

they do not change

Question 4

A radioactive substance has decayed to 1/16 of its original sample, __half-lives have passed.

Accepted Answer

4

Question 5

This occurs when lighter elements are transformed into heavier elements in the laboratory.

Accepted Answer

artificial transmutation

Question 6

Temperature, pressure & surface area all affect nuclear decay rates.

Accepted Answer

FALSE

Question 7

Objects that can be carbon dated may include

Accepted Answer

bones, teeth & ancient wood tools.

Question 8

Carbon reacts with oxygen in the atmosphere to produce

Accepted Answer

Carbon Dioxide

Question 9

Radioisotope decay rates can range from milliseconds to millions or billions of years.

Accepted Answer

TRUE

Question 10

The process of determining an object's age by knowing the half-lives of radioisotopes is called

Accepted Answer

radioactive dating.

Question 11

Thorium-234 has a half-life of about 24 days. It would take ___days for 3/4 of it to decay.

Accepted Answer

48

Question 12

After 6 half-lives a 10 gram radioactive substance will have

Accepted Answer

0.156 grams of its original substance., 1/64 of its original substance left.

Question 13

How are radioactive isotope decay rates best described?

Accepted Answer

by using a specific decay rate called a half-life

Question 14

Nuclear decay rates are ___, unlike chemical reaction rates.

Accepted Answer

constant

Question 15

Carbon-14 dating can be used

Accepted Answer

only on objects that were once alive.

Question 16

10 grams of C-14 (H.L. 5730 years) will decay to ___ grams after 11, 460 years.

Accepted Answer

2.5

Question 17

How is carbon-14 formed?

Accepted Answer

cosmic rays colliding with N-14 in the upper atmosphere

Question 18

After two half-lives, ___ of the original radioisotope remains unchanged.

Accepted Answer

1/4

Question 19

Uranium-238 half-life is 4.5 billion years. The Earth is about 4.5 billion years old -so

Accepted Answer

the Earth had twice as much uranium when first formed, about 1/2 of all the uranium on Earth has decayed into lead

Question 20

Elements with atomic numbers greater than uranium (92) are known as

Accepted Answer

transuranium elements.

Questions 20