Nuclear Chemistry

Significant Figures (sf)

Digits that are meaningful to the precision of a measurement.

Fill in the Blank: All non-zero digits are __________ (___, e.g., 424 has 3 sf).

significant figures.

Significant Figures Rule 1

All non-zero digits are significant.

Significant Figures Rule 2

Zeros between non-zero digits are significant.

Fill in the Blank: Zeros between non-zero digits are __________ (e.g., __________ has 5 sf).

significant; 40024.

Significant Figures Rule 3

Leading zeros are not significant.

Fill in the Blank: Leading zeros are __________ (e.g., 024 has 2 sf).

not significant.

Significant Figures Rule 4

Trailing zeros in a number with a decimal point are significant.

Fill in the Blank: Trailing zeros in a number with a decimal point are __________ (e.g., __________ has 5 sf).

significant; 42.400.

Scientific Notation Check

If zeros disappear when written in scientific notation, they are not significant.

International System of Units (SI)

A system of standardized units used in measurement.

Fundamental Units

Basic SI units including mass (kg), length (m), time (s), electric current (A), temperature (K), luminous intensity (cd), and amount of substance (mol).

Fill in the Blank: The fundamental unit for mass is __________.

kilogram (kg).

Define Derived Units

Units generated from fundamental units, like force (N).

Unit Analysis for Pressure

Pressure (P) = Force/Area = (kg·m·s^-2)·m^-2 = kg·m^-1·s^-2.

Precision Rule in Calculations

Answers must use the same number of significant figures as the datum with the fewest significant figures.

Exact Numbers

Conversion factors that do not limit precision.

Fill in the Blank: Round only at the __________ of a calculation.

end.

Atomic Mass Unit (a.m.u.)

Defined by setting the mass of carbon-12 to exactly 12 a.m.u.

Comparison of Particles: Proton

Charge +1, Mass 1.00726 a.m.u.

Comparison of Particles: Neutron

Charge 0, Mass 1.00865 a.m.u.

Comparison of Particles: Electron

Charge -1, Mass 0.000549 a.m.u.

Fill in the Blank: The charge of a positron (e+) is __________ and mass is __________.

+1, 0.000549 a.m.u.

Nuclear Notation Format

The format used is ${}^{A}_{Z}X$, where A is the mass number and Z is the atomic number.

What are Isotopes?

Nuclides that share the same atomic number but have different mass numbers.

Example Isotopes of Carbon: {12, 13, 14}

C: 12 (98.89% stable), 13 (1.11% stable), 14 (unstable).

Radioactive Decay Process

Radioactive nuclei undergo decay until reaching a stable state.

Fill in the Blank: Applying radioactive decay, a parent radionuclide transforms into a __________ nuclide.

daughter.

First-Order Kinetics

Radioactive decay follows first-order kinetics, meaning the rate depends on the amount of reactant present.

Half-Life (t_{1/2})

The time required for the number of nuclei to decrease to half its original number.

Activity (A) Definition

The rate of emission or negative rate of disappearance of the parent nuclide.

Specific Activity

The activity per unit mass of the radionuclide measured in Bq/g.

Molar Activity

The activity per mole of radionuclide measured in Bq/mol.