1. Announcements ● Chapter 3 reading and problems will be posted on Wednesday. ● Quiz 2, Today (sections 1.6-2.8). ● Reminder: download handout for this week's lab—Do prelab pages. No Clicker Questions Today ● Exam Wed. To speed getting started do not enter class until I let you in. ● Still not successfully signed up for e-mail discussion list: Xoing Chang & Jazz Singh.

2. Fission reactions. – 239 93 Np + 1 0 n --> 142 56 Ba + 4 1 0 n + 94 37 Rb, – Chain reactions – Releases energy – Nuclear reactors. Making artificial isotopes by fusion of nuclides using accelerators. Measuring radioactivity – Units: counts/s = Bq & Ci = 3.7 x 10 10 Bq – Measure with film or Geiger Counter. Biological effects—ionizing radiation damages by ionizing molecules and breaks them into reactive fragments. Review

3. Radioactive Dating Expression for fraction left at time, t: Solving for t: t =t 1/2 {1/ln(0.5)}ln(A t /A o ) Carbon Dating –Use 14 C/ 12 C ratio for A t and A o –Use new sample to get A o Other isotopes: A o =stable product + remaining radionuclide; A t = remaining radionuclide.

4. Chapter 1-Matter and Its Origins A. States of matter (s, l, g) B. Pure substances vs. Mixtures (homo vs. heterogeneous) C. Elements and Atoms D. Compounds and Molecules E. Physical properties (color, state, density, conductivity, thermal conductivity, metallic character) F. Physical vs. Chemical Change G. Scientific Process/Method H. Big Bang energy->quarks->n -> p + e - -> nucleons -> atoms -> stars/galaxies I. Significant figures/digits (accuracy and precision) J. Properties of light 1)Light is a wave:  =c/   K. metric prefixes (n, , m, c, k) L. Radioactive Decay/Half-Life M. Atomic Particles (neutrons, protons, electrons) N. Atomic Number/Atomic Mass/Isotopes O. Temperature (K, ˚C, ˚F) P. Black body radiation: