Chem 1100 1st Edition Lecture 4 Outline of Last Lecture I. Characteristics of Chemical EquationsII. Balancing EquationsIII. Balancing Equations ExamplesIV. Ozone: What is it?V. Atomic Structure & PeriodicityOutline of Current Lecture I. IsotopesII. How Particles ReactIII. Molecules & ModelsIV. Octet RuleV. Waves of LightVI. Frequency & WavelengthCurrent LectureI. Isotopesa. Different number of neutrons: Isotopesb. Changing the number of neutrons changes how much the atom weighs and can also affect the stability. i. Examples: 3 kinds of Carbon (6p, 6n, 6e) 99% Carbon -12 , (6p, 7n, 6e) 1% Carbon -13, (6p, 8n, 6e) Almost 0% Carbon -14 (radioactive)c. Sum of the protons and neutrons to specify the type of isotope you’re working withd. Neutrons: uncharged, add mass to the atom, if you change the number of neutrons you still have the same kind of atom, and they still react the same way, but the mass is different, and it could affect the stability.e. Isotope: same number of protons, different number of neutronsi. Atomic Number (Z): # of protons in nucleusii. Mass Number (A): # of protons + # of neutronsiii. Element (X) 1. AZ2. A, Z, X are not significant letters. They are just placeholders to show you that when you are writing which isotope you are These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.talking about that’s how it is displayed. With the Atomic mass in the lower left hand corner of the element symbol (X). And with the mass number in the upper left hand corner of the element symbol (X). X is just a placeholder for any element you are working with from the periodic table. For example: X could be anH, which would mean you are working with hydrogen. Or it couldbe a C, which would mean you are working with carbon.iv. If you take the atomic number and subtract it from the mass you get the number of the neutrons in the isotope. v.f. Changing # of particlesi. Change # of protons: Change identityii. Change # of neutrons: Isotopeiii. Change # of electrons: IonII. How Particles Reacta. Valence Electronsi. Large atoms – many electron “layers” – organized into different energylevelsii. Shells/layersiii. Valence electrons are in the outermost layeriv. Valence electrons are the ones involved in chemical reactionsb. Noble gases are stable. Nonreactive. c. The atoms want the same # of valence e- as nearest group 8A element.d. For example: It’s easier for Fluorine to gain one electron to become like Neon instead of losing 7 electrons to become like Lithium.III. Molecules & Modelsa. Molecule: two or more atoms boundb. Covalent Bond: when two atoms share electronsi. Two atoms share two electrons: (single) covalent bondii. Hydrogen tends to do this a lot. They share electrons because they aremore stable together than they are separately. iii. Covalent Bonds: Nonmetal – Nonmetal tend to form covalent bondsc. Lewis Dot Structure H• + H •  H:Hd. Line (s) between atomse. Lines between atoms mean the same as two dotsIV. Octet Rulea. Atoms prefer to have 8 Valence electronsb. Shared and unsharedc. Exceptions: H, He (2 valence electrons), and a few othersd. Double bond: 4 electrons shared between two atomse. Triple bond: 6 electrons shared between two atomsf. Ex: of triple bond :N = N:g. How does Ozone protect us from UV light? V. Waves of Lighta. There are different kinds of light. And what makes light different is the differentkind of wavelengths of light.b. Wavelength: the distance from one peak to the next peak. c.d. Frequency: if you can define a point in space, how many waves pass through that point in a second.e. The relationship between wavelength and frequency: The purple wave above has a higher frequency. The red wave above has a longer wavelength.Wavelength and frequency are inversely related. Which means that If the frequency is higher, the wavelength will be shorter. And if the frequency is lower, the wavelength will be longer. f. All light travels at the same speed. The speed of light. 3.00 x 10^8 m/s.VI. Frequency & Wavelength λa. Units of frequency? Sec ^ -1 i. Which means waves per second, S ^ -1 , or inverse seconds, or secondsto the minus 1, or cycles per second (cps), Hz (hertz).ii. Number of waves that pass through a point in space in 1 second.iii. Symbol: v (Greek: nu) also stands for frequency.iv. Hz (hertz) means waves per second or inverse seconds.b. Wavelength λ :i. Different λ = different kind of lightii. Measured in nm, nanometers, one billionth of a meteriii. 1 x 10 ^ 9 nm = 1 miv. As frequency goes up, wavelength goes down.v. You can convert wavelength and frequencyvi. In meters  λ = C/V C= 3.00 x 10^8 m/svii. A radio station is 103.5 FM. What wavelength does it broadcast?1. 103.5 FM = 103.5 MHz = 103.5 million s^ -12. λ = 3.00 x 10^8 m/s = 2.9 m approx: 10