LECTURE 1.1 STD. 1A &E: INTRO TO THE ATOM

TAKING NOTES IN CHEMISTRY Draw a line to split the page into two sections Titles of the slides  left side of the page Bulleted points  right side of the page Things in RED  do not have to write down This in BOLD BLUE  key terms you must highlight

CA STANDARDS  Std. 1a: Students know  Std. 1a: Students know how to relate the position of an element in the periodic table to its atomic number and atomic mass.  Std. 1e Students know  Std. 1e Students know the nucleus of the atom is much smaller than the atom yet contains most of its mass.

HOW DO CHEMISTS CHARACTERIZE THE ATOM?

I. THE ATOM Smallest particle any matter can be divided into. The atom has a diameter b/w 0.1 – 0.5 nm Point of reference: A basketball has a diameter of 234,500,000 nm

II. THREE TYPES OF SUBATOMIC PARTICLES All atoms contain the following subatomic particles: 1.Protons 2.Neutrons 3.Electrons

III. PROTONS Protons are found in the nucleus of an atom. The nucleus is located in the center of the atom. Protons have a positive charge. We say that their charge is +1

IV. NEUTRONS Neutrons are found in the nucleus of an atom. Neutrons do not have a charge. They are neutral James Chadwick discovered the neutron in 1932!

V. MASS OF PROTONS AND NEUTRONS Protons and neutrons have the same mass. Each subatomic particle has a mass of 1 amu. – amu = atomic mass unit

VI. ELECTRONS Electrons are found in the electron cloud. The electron cloud surrounds the nucleus of an atom. Electrons have a -1 charge

VII. MASS OF ELECTRONS Electrons have a mass that is amu. Electrons do not contribute to the weight of an atom.

VIII:NUCLEUS & ELECTRON CLOUD Nucleus is VERY TINY but contains 99.9% of the atom’s mass, VERY HEAVY. (because protons and neutrons each have mass of 1 amu) Electron cloud has a LARGE VOLUME but contains very little mass. (Electrons have no mass.)

HOW SMALL IS AN ATOM? VIDEO

ATOMIC # & MASS

IX: ATOMIC NUMBER Identifies a particular atom. (ID # of the element)  Equals the # protons and the # of electrons  The Periodic Table  organized by increasing atomic number.

X: ATOMIC MASS Average mass of all ISOTOPES of that element. Atomic mass = mass of protons + mass of neutrons #NEUTRONS = Atomic mass – Atomic # 99.9% of atomic mass is located in the atom’s _____________. NUCLEUS

XI: ISOTOPES are atoms of the same element with different masses due to different number of neutrons. # PROTONS STAY THE SAME! Ex: C-14 Find: Atomic #, Mass, P, N, E. ISOTOPIC MASS

VALENCE ELECTRONS Electrons on the outermost shell (orbital). Participate in bonding with other atoms. First orbit holds upto 2 e- All other orbits hold upto 8 e-

TASK Use the periodic table to find an element with the same letters as your NAME. (2) a)What is the atomic number b)What is the atomic mass c)Draw a Bohr Model to show the following: How many protons? How many neutrons? How many electrons? d)How many valence e- does it have?

HOW TO DO A P.O.G.I.L Structured group work—Teams are Picked a)Manager b)Spokesperson c)Time keeper d)Reflector Teams will be observed to see whether the guidelines and classroom expectations are being followed Points will be deducted otherwise

EXPECTATIONS 1.Do my tasks—do them well! 2.Be where I belong 3.Help others in need 4.Follow directions 5.BE RESPECTFUL!