2046chapter21

2046chapter21 - Chapter 21 Nuclear Chemistry: the study of...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Chapter 21 Nuclear Chemistry: the study of nuclear reactions Learning goals and key skills: h Write balanced nuclear equations h Know the difference between fission and fusion h Predict nuclear stability in terms of neutron-to-proton ratio h Calculate ages of objects or amounts of materials from data on nuclear abundances using the half-life of a radioactive material h Convert between nuclear activity units h Calculate mass and energy changes for nuclear reactions h Understand the meaning of radiation dosage terms h Understand the biological effects of different kinds of radiation “For the moment, the discovery will be known as ununseptium, a very unwhimsical Latinate placeholder that refers to the element’s atomic number, 117 . “
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 The nucleus The nucleus is comprised of the two nucleons : protons, p + • neutrons, n 0 Radionuclides are nuclei that are radioactive i.e., they will spontaneously emit radiation. Atoms containing these nuclei are called radioisotopes . Atomic and Mass Numbers 12 6 C Symbol Mass number Atomic number (optional) Atomic number: equal to the number of protons in the nucleus. All atoms of the same element have the same number of protons. Mass number: equal to the sum of the number of protons and neutrons for an atom. Isotopes atoms with identical atomic numbers but different mass numbers 12 6 C 14 6 C carbon-12 carbon-14 1 1 H 2 1 H 3 1 H Hydrogen or protium deuterium, D tritium, T
Background image of page 2
3 Isotopes 238 92 U 235 92 U 234 92 U abundance: 99.27% 0.72% 0.0055% half-life 4.47 billion years 700 million years 246 000 years It is not uncommon for some nuclides ( radionuclides) of an element to be unstable, or radioactive . There are several ways radionuclides can decay into a different nuclide. α , β and γ Radiation β -ray High speed electron: charge= -1 , mass= 9.10 × 10 -28 g α -ray He core: charge= +2 , mass= 7295 × mass of electron γ -ray Electromagnetic Radiation: no charge , no mass α , β and γ Radiation α -ray β -ray γ -ray symbol or or or charge 2+ 1- 0 mass 6.65 × 10 -24 g 9.11 × 10 -28 g 0 g 4.00151 amu 0.00549 amu penetrating paper 0.5 cm Pb 10 cm Pb ability 4 2 α 0 -1 β 4 2 He 0 -1 e γ 0 0 γ
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 Types of Radioactive Emissions Other common nuclear particles neutron proton positron symbol or or charge 0 1+ 1+ mass 1.675 × 10 -24 g 1.673 × 10 -24 g 9.11 × 10 -28 g 1.00867 amu 1.00728 amu 0.00549 amu 0 +1 β 1 0 n 1 1 p + β 0 +1 e Nuclear reactions Alpha decay Radium-226 emits an alpha particle. Beta decay
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 17

2046chapter21 - Chapter 21 Nuclear Chemistry: the study of...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online