1 Chapter 1 Origins

2 The Origin of Matter The Big Bang Occurred 12 to 15 billion years ago. Space energy and matter underwent an explosive expansion. How do we know? The key is in our ability to measure. We communicate our measurements using the SI System.

3 Key Events in the History of the Universe

4 SI Units

5 Matter and Energy Matter: The physical material of the universe. Occupies space and has mass. Energy: The capacity to do work. That which is required to oppose a natural attraction. Mass corresponds to energy (Einstein). E = mc 2

6 Exercise 1.1: E = mc 2 Energy released when kg uranium is converted to kg other elements. E = (1 x kg) x (3 x 10 8 m/s) 2 E = (1 x kg) x (9 x m 2 /s 2 ) E = (1 x 9) x (10 -3 x ) x (kg m 2 /s 2 ) E = 9 x J

7 But How Do You Know? Direct Evidence: That which we, ourselves, observe. Indirect Evidence: The clues that, when taken together, provide substantial evidence that an event has occurred without our having seen it.

8 Subatomic Particles Three principal building blocks of matter: proton, neutron, electron Charges: p = +1 n = 0 e – = –1 Masses p = 1 amu n = 1 amu e – = amu

9 Fundamental Forces Electromagnetic force: Responsible for magnetism and electronic attractions and repulsions. Gravity: Causes all objects with mass to be attracted to one-another. Strong nuclear force: Binds protons and neutrons together. Weak nuclear force: transformations in the subatomic particles.

10 Elemental Symbols

11 Practice: protons, neutrons, electrons, symbols SymbolElementProtonsNeutrons W110

12 Answers: protons, neutrons, electrons, symbols SymbolElementProtonsNeutrons N78 U94145 W74110 Mn2530

13 The Three States of Matter

14 Densities

15 Life Cycle of a Star

16 Elements, Compounds and Mixtures Elements: Contain only one kind of atom (Ar, C, N, Sb) Compounds: Contain different kinds of atoms chemically bonded together (CO 2, H 2 O, C 12 H 22 O 11 ) Mixtures: Blending of substances not chemically-bound to each other (saltwater, concrete)

17 Molecules and Ions Molecules are distinct particles composed of 2 or more atoms linked together (O 2, NH 3, CH 3 OH). Atoms in molecules are held together by covalent bonds. Ions are charged particles. Ionic bonds involve attraction of opposite charges. Ionic compounds include NaCl and CaO.

18 Practice: protons, neutrons and electrons in ions SymbolProtonsNeutronsElectronsCharge

19 Answers: protons, neutrons and electrons in ions SymbolProtonsNeutronsElectronsCharge Sn Fe+3

20 Miller-Urey Experiment