SUBATOMIC PARTICLE LOCATION (in the atom) RELATIVE CHARGE MASS (amu) In nucleus Proton +1 1 Neutron In nucleus 0 1 Electron Outside of nucleus (electron cloud) -1 0 Do Now: Fill in the table below
Chemistry 9/17/13 Mrs. Turgeon • “Great minds discuss ideas; average minds discuss events; small minds discuss people.” – Eleanor Roosevelt • DO NOW: In your notes, write down everything you know about an atom
Chemistry 9/18/13 Mrs. Turgeon “Do what others won’t to achieve what others don’t” – anonymous DO NOW: In your notes, answer: “What does the atomic number of an element represent?”
Honors Chemistry 9/18/13 AGENDA • Finish POGIL worksheet (15 minutes) • Check-in with the class (spokespersons be ready to share your group’s answers) • Start Isotopes POGIL YOUR REVIEW OF LIT FOR SCIENCE FAIR IS DUE NEXT WEDNESDAY!!!!!!!!!!!!!!
O O S O O H H Interpretation of a Chemical Formula Sulfuric Acid H2SO4 Two atoms of hydrogen Four atoms of oxygen One atom of sulfur
- e + - e + e - e + + + + e - + e e - e + e + e Models of the Atom Dalton’s model (1803) Democritus’s model (400 B.C.) Thomson’s plum-pudding model (1897) Rutherford’s model (1909) Bohr’s model (1913) Charge-cloud model (present) 1897 J.J. Thomson, a British scientist, discovers the electron, leading to his "plum-pudding" model. He pictures electrons embedded in a sphere of positive electric charge. 1911 New Zealander Ernest Rutherford states that an atom has a dense, positively charged nucleus. Electrons move randomly in the space around the nucleus. 1926 Erwin Schrodinger develops mathematical equations to describe the motion of electrons in atoms. His work leads to the electron cloud model. 1803 John Dalton pictures atoms as tiny, indestructible particles, with no internal structure. 1913 In Niels Bohr's model, the electrons move in spherical orbits at fixed distances from the nucleus. 1800 1805 ..................... 1895 1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1932 James Chadwick, a British physicist, confirms the existence of neutrons, which have no charge. Atomic nuclei contain neutrons and positively charged protons. 1924 Frenchman Louis de Broglie proposes that moving particles like electrons have some properties of waves. Within a few years evidence is collected to support his idea. 1904 Hantaro Nagaoka, a Japanese physicist, suggests that an atom has a central nucleus. Electrons move in orbits like the rings around Saturn. Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 125
Chemistry 9/20/13 Mrs. Turgeon • DO NOW: • In your notes: “What • does the mass number • in the Isotopic chemical • Symbol represent?”
Chemistry 9/20/13 Mrs. Turgeon Agenda • Review Isoptopes • Review Atom POGIL • Review Beanium Lab
Mass # Atomic # Isotopes • Atoms of the same element with different mass numbers (because they have different #’s of neutrons) • Atomic symbol: • Hyphen notation: Boron-11
11 10 5B 5B Isotopes Fill in the blanks below… # of # ofatomic mass Protons neutrons number number symbol A 5 5 5 10 = proton = neutron (no electrons shown) 5 6 5 11 B
Isotopes - practice 17 37 17 17 20 • Chlorine-37 • atomic #: • mass #: • # of protons: • # of electrons: • # of neutrons: Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Isotope Worksheet 9. Which two nuclei are isotopes of each other? Same element, different mass numbers
Beanium Lab The 3 Isotopes of Beanium represent the SAME ELEMENT. They are exactly the same except for the number of neutrons! Let’s compare our model (Beans) to a real element (Carbon)
+ + + + + Carbon-14 Carbon-12 + Neutrons 6 Protons 6 Electrons 6 Neutrons 8 Protons 6 Electrons 6 + + + + + + Carbon-12 and Carbon-14 Electrons Electrons Nucleus Nucleus
Mass # Mass # Atomic # Atomic # Carbon-12 Carbon-14
Beanium Lab Let’s do the last problem together. Who wants to share their data?
IONS • Ions are atoms that have lost or gained electrons. • An atom that loses an electron becomes a positive ion (CATION) • An atom that gains an electron becomes a negative ion (ANION)
EXAMPLES OF IONS • A magnesium atom loses two e- and becomes… • A chlorine atom loses two e- and becomes… • When these two ions bond, what compound is formed? • Magnesium chloride, MgCl2 (more on this next chapter!) Mg2+(a cation) Cl1- (an anion)
HOMEWORK – • Read 4-10 & 4-11 • #’s 65-73,80-83 • Study for a possible element quiz next week!