Nuclear Chemistry

Question 1

What are the three types of ionizing radiation?

Answer 1

Alpha (α), Beta (β), Gamma (γ)

Question 2

What is the physical basis of each form of ionizing radiation?

Answer 2

α-radiation is a He nucleus
β-radiation is an electron
γ-radiation is electromagnetic radiation

Question 3

What are two other particles which can be emitted from an atomic nucleus?

Answer 3

Positrons: like an electron but positively charged β+

Neutrinos: low mass particle, written as v

Question 4

Which particle is involved in alpha emission?

Answer 4

In this type of radioactive emission, a helium particle is released (AMU 4 g/mol, Atomic # 2)

Question 5

What process is involved in beta emission?

Answer 5

A neutron changes into a proton, then an electron is emitted from the nucleus as a result.

The atomic number increases by 1 while the atomic mass stays the same.

Question 6

Under which condition does gamma radiation take place?

Answer 6

This type of radiation occurs along with or after one of the other types of radiation when the new nucleus formed is in an excited state.

Question 7

How is an atom is an excited state notated?

Answer 7

This atomic state is indicated by the letter ‘m’ placed next to the atom’s atomic mass number.

Question 8

What characteristic makes transuranic elements different from all other elements?

Answer 8

This type of element does not occur naturally. Instead, this type of element is made in a particle accelerator by smashing two nuclei together.

Question 9

What is a special use of the element Americium (Am)?

Answer 9

This transuranic element is used in smoke detectors.

Question 10

What is a special use of Plutonium (Pu)?

Answer 10

This transuranic element is utilized as nuclear fuel.

Question 11

The Uranium-238 decay series depicts Uranium-238 undergoing which two processes?

Answer 11

This series depicts both alpha and beta decay of Uranium-238.

Question 12

What is nucleosysthesis?

Answer 12

T process of making the
elements. This tends to occur in stars…and there
are several different processes.

Question 13

What are the two dominant theories of nucleosynthesis?

Answer 13

Big Bang Nucleosynthesis and Stellar Nucleosynthesis.

Question 14

What does Big Bang nucleosynthesis say about the formation of hydrogen and helium?

Answer 14

This theory states that hydrogen and helium were formed within the first few minutes of the start of the universe

Question 15

What does the theory of Stellar Nucleosynthesis say about the formation of elements?

Answer 15

This theory states that heavier elements are made from the nuclear fusion of hydrogen and helium in stars

Question 16

What is the CNO process and how does it relate to the formation of hydrogen and helium?

Answer 16

…

Question 17

What is the triple alpha process?

Answer 17

This process occurs when helium nuclei (alpha particles) fuse with each other and with the heavier nuclei that
they form.

Question 18

What are two accessory examples of nuclear fusion?

Answer 18

Lithium and carbon burning.

Question 19

At which element do most nuclear reactions stop fusing to form new elements?

Answer 19

Iron stops these reactions from continuing.

Question 20

What happens in a supernova and what is the product of this?

Answer 20

Within this star, free neutrons interact with heavier nuclei and produce the really heavy
elements to produce new elements which are heavier that Iron.

Question 21

What is the atomic mass of iron?

Answer 21

56 grams/mol

Question 22

What are the two types of supernova nucleosynthesis and what do they indicate about the process?

Answer 22

The ‘r’ type indicates a rapid speed of this process, while the ‘s’ type indicates a slower speed for this process.

Question 23

What does the nucleosynthesis periodic table indicate?

Answer 23

This periodic table indicates the relative energy required for the synthesis/formation of each element.

Question 24

Why do most nucleosynthesis processes stop at Fe?

Answer 24

Most nucleosynthesis processes stop at this element because its binding energy is incredibly high.