CHEM 1030 Cagg Chapter 2 Notes
CHEM 1030 Cagg Chapter 2 Notes Chem 1030
Popular in Fundamental Chemistry I
Popular in Chemistry
This 4 page Class Notes was uploaded by Amy Notetaker on Saturday January 30, 2016. The Class Notes belongs to Chem 1030 at Auburn University taught by Brett A Cagg in Spring 2016. Since its upload, it has received 89 views. For similar materials see Fundamental Chemistry I in Chemistry at Auburn University.
Reviews for CHEM 1030 Cagg Chapter 2 Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 01/30/16
Lecture / Book Notes: Chapter 2 (1/25/2016) CHEM 1030 Cagg Highlighted: Vocab ----- Highlighted: People ----- Highlighted: Formula/Numbers The first test WILL NOT heavily emphasize sections 2.1-2.4, so you can skim through them. It WILL heavily emphasize 2.5-2.7!!! Section 2.1 v Atoms • Atoms: are the building blocks and smallest units of matter - The philosopher, Democritus was the first to propose this idea - An English scientist and school teacher, John Dalton, was the first to agree/formalize with the idea of matter having atoms - Atoms are made up of tiny subatomic particles • Element: contain a unique form of the same atom (each element has a different form of atoms), which cannot be divided into 2 or more simpler substances - Example: oxygen, nitrogen, iron, sulfur Section 2.2 v Discovery of electrons • Radiation: is the transmission of energy in the form of waves • Cathode ray tube: also known as the electron beam, is a glass tube with metal plates on each end, which has all air, sucked out from it. This device detects electrons using radiation. • Cathode: is a negatively charged plate within the cathode ray which produces radioactive waves called cathode rays • Anode: is a positively charged plate within the cathode ray • Columb’s law: like charges push against one another and opposite charges come towards one another - Example: magnets • The rays in a cathode ray tube, are a stream of negative particles (electrons), which was discovered by the English physicist J.J. Thomson - Thompson determined the charge-to-mass ratio of the electrons as ▯ 1.76 × 10 Columbs per gram • R.A. Millikan who was an American physicist, determined the charge of an electron by examining the motion of oil drops • The mass of an electron is 9.10 × 10 ▯▯▯g v Radioactivity • Wilhelm Rontgen, a German physicist discovered X-rays. • X-rays: rays that are able to penetrate matter and cause materials to give off a fluoresce light. They do no have charged particles due to them not being deflected by anything. - X-rays are only produced when exposed to cathode rays • Antoine Becquerel, a French physicist discovered radiation • Radioactivity: a spontaneous emission of rays that are highly energetic and cannot be deflected due to anything. There are 3 types of radioactive emissions: - Alpha α rays: have positively charged particles, which are called alpha particles. These are deflected away from a positively charged plate. - Beta β rays: have negatively charged particles called beta particles (also known as electrons). These are deflected away from negatively charged plates. - Gamma y rays: these have no charge v Proton and the nuclear model of the atom • The plum pudding model: an idea proposed by Thomson saying that electrons were embedded into the atom like “raisins in a scoop of rum ice cream”; it was the accepted theory for quite a while. • Ernest Rutherford, a student of Thomson’s and a physicist, claimed that atoms were mostly empty space, he also said the atom had a very dense core called the nucleus, with positive particles (protons) in it. • An atomic radius is about 100 pm in radius ▯▯ • The radius of the atom’s nucleus is 5 × 10 pm • Protons and neutrons are located INSIDE of the nucleus, and the electrons are located AROUND the nucleus. v The neutron • James Chadwick, an English physicist discovered the neutrons (which are neutral particles) in the nucleus Section 2.3 v Atomic number, mass number, and isotopes • The atomic number: the number that defines the element, it also represents the number of protons that are in the nucleus of that atom. - Example: Carbon’s atomic number is 6, so a carbon atom has 6 protons in its nucleus - Note that the number of protons can NEVER change, or it will change the element, so if you added one more proton to carbon, it would then have 7 protons and become nitrogen. • The atomic mass number: the total number of protons and neutrons that are in the nucleus of an element’s atom. • The nucleus usually contains has the same amount of protons as it does neutrons, so carbon has 6 protons, and 6 neutrons; however, this is not the case with isotopes. • Isotopes: are atoms which have the same atomic number, but different atomic mass, (the number of neutrons is different from the number of protons). • To find the protons of an element, look at the atomic number • To find the neutrons of an element, subtract the atomic number from the atomic mass. • To find the electron of an element, look at the atomic number, there is the same amount of protons as there are neutrons. Section 2.4 v Nuclear Stability • The nucleus has most of the atom’s mass, but it’s a small part of an atom’s total volume. • The highest known density of an element is 22.6 g/cm , which is for iridium. • The stability of an atom’s nucleus is determined by the difference between coulombic repulsion and short range attraction. Section 2.5 v Average atomic mass • Atomic mass: the mass of an atom in atomic mass units (amu) • You calculate average atomic mass (deals with isotopes) by this formula: ((normal mass) x (natural abundance of normal x 100)) + ((isotope mass) x (natural abundance of isotope x 100)) - To calculate the average atomic mass of carbon 12 and carbon 13 you would do: ((12.00000 amu) x (98.93 x 100)) + ((13.003355 amu) x (1.107 x 100)) = 12.01 amu Section 2.6 v The periodic table • The periodic table: consists of 118 elements that are grouped according to their physical and chemical properties. • The elements are arranged into periods (horizontal) and groups/families (vertical). • Metals: good conductors of heat and electricity • Nonmetals: bad conductors of heat and electricity • Metalloid: in between metal and nonmetal properties (they are okay conductors of heat and electricity). • Group 1A: the alkali metals (Li, Na, K, Rb, Cs, and Fr) • Group 2A: the alkaline earth metals (Be, Mg, Ca, Sr, Ba, and Ra) • Group 6A: the chalcogens (O, S, Se, Te, and Po) • Group 7A: the halogens (F, Cl, Br, I, and At) • Group 8A: the noble gases (He, Ne, Ar, Kr, Xe, and Rn) • Groups 1B, 3B-8B: transition elements/transition metals Section 2.7 v The mole • Mole: unit of measurement that shows the quantity in any substance that has the same number of particles (atoms) found in 12.000 grams of carbon 12. It is like a dozen (12) or a gross (144). • Avogadro’s number: the number of atoms in 12.000 grams of carbon 12 ▯▯ (6.022 x 10 ) v Molar mass • Molar mass: the mass in grams of one mole of a substance. • Molar mass and Avogadro’s number can be used to convert to and from mass, moles, and number of atoms.
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'