Nuclear Phenomena Flashcards Preview

MCAT Physical Sciences > Nuclear Phenomena > Flashcards

Flashcards in Nuclear Phenomena Deck (15)
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1
Q

Atomic Number (Z)

A

The number of protons in the nucleus

2
Q

Mass Number (A)

A

A = N + Z

3
Q

Isotope

A

Same element, different numbers of neutrons

4
Q

Atomic Mass Unit

A

1 amu = 1/12 mass of neutral Carbon-12 atom = 1.66 X 10^-27 kg = 1.66 X 10^-24 g

5
Q

Nuclear Binding Energy

A

Energy that holds nucleus together defined by E = mc^2

6
Q

Mass Defect

A

Difference between atom’s atomic mass and sum of masses of its protons and neutrons.

7
Q

Fusion

A

Two or more smaller nuclei combine to form larger nucleus

8
Q

Fission

A

Large nucleus splits into smaller nuclei

9
Q

Why do nuclear fusion and nuclear fission release energy?

A

initial mass > final mass

10
Q

Alpha Decay

A

Emission of alpha particle (a Helium atom)

Subtract two protons and two neutrons

11
Q

Beta Decay

A

Emission of a beta particle (an electron)

Add a proton when electron emitted, subtract one when positron emitted

12
Q

Gamma Decay

A

Emission of high energy photons, does not change mass or proton number

13
Q

Electron Capture

A

Nucleus captures inner-shell electron leading to neutron formation, so atomic number decreases by 1, but atomic mass remains the same

14
Q

Half-Life

A

T(1/2) = ln 2/λ

Fraction of original nuclei remaining after n half-lives is (1/2)^n

15
Q

Exponential Decay

A

-λn = Δn/ Δt
Number of nuclei that decayed in time t = n(0) - n
n = n(0)e^-λt