Chem Final Study Guide PDF

Study Guide Chem Final (ANYTHING HIGHLIGHTED IN BLUE IS NOT FINISHED) LEARNING TARGET 1 MATTER BASICS: ​ Chemistry is the study of matter including its composition, its properties, how it changes, how it is affected by forces and interacts with energy...

Study Guide Chem Final (ANYTHING HIGHLIGHTED IN BLUE IS NOT FINISHED) LEARNING TARGET 1 MATTER BASICS: ​ Chemistry is the study of matter including its composition, its properties, how it changes, how it is affected by forces and interacts with energy ○​ Means to work with new and sophisticated fluids, and other items ​ Matter is any substance with a solid form; that cannot be created or destroyed MATTER NON-MATTER -​ Cells -​ Fire -​ Steam -​ Love -​ Bacteria -​ Heat -​ Dust -​ Light -​ Water -​ Gravity -​ Stars -​ Magnetic force -​ Oxygen -​ Sound waves -​ Salt -​ Rainbow -​ Rocks -​ Electricity -​ Water ​ If something is NOT matter, it can be: ○​ Energy (light, heat, sound) ○​ Forces (strong nuclear, weak nuclear, electromagnetic) ○​ Abstract concepts (love, freedom, justice and knowledge) LEARNING TARGET 2 - THE ATOMIC SPECTRUM ​ 3 subatomic particles: Protons, Neutrons, and Electrons PROTONS ​ Positive particle ​ Location: found in the nucleus ​ Charge: Positive +1 ​ Weight (AMU) : 1 NEUTRONS ​ Neutral particle (neither positive nor negative) ​ Location: Found in the nucleus ​ Charge: 0 ​ Weigh: 1 (amu) ELECTRONS ​ Negative particle ​ Location: on the outer shell of the nucleus ​ Charge: -1 ​ Weight (amu) 0 IONS AND ISOTOPES: ​ Isotopes are the atoms of the same element with different numbers of neutrons ​ For an atom to be… ○​ Neutral, it has no charge ○​ An isotope, it needs to be of the same number of protons, but with different numbers of neutrons ○​ An ion, must gain or lose electrons  ​ The subatomic particles that affect the stability of an atom is ​ Amount of binding energy ​ Tighter/looser bound ​ Mass defect produced ​ Based on when nuclei form, there is less mass converted into nuclear binding energy ​ Can release more energy during fusion ​ When isotopes are unstable (due to the ratio of neutrons to protons NOT falling in a stable range) it may undergo radioactive decay which is mediated by weak force. LEARNING TARGET 4 - FUNDAMENTAL FORCES: ​ Electromagnetic forces occur between any two charged particles. ○​ Electric forces cause an attraction between particles with opposite charges and repulsion between particles with the same charge. ○​ Particles which contain electric charge. (negatively charged electrons and positively charged protons.) ○​ Binds negatively charged electrons to positively charged atomic nuclei ○​ The fundamental force is the strong nuclear force which holds the nucleus of atoms together. FUNDAMENTAL FORCES: ​ Gravitational force ​ Strong force ​ Weak force ​ Electromagnetic force ​ An atom is stable if the forces among the particles that makeup the nucleus are balanced. ​ An atom is unstable (radioactive) if these forces are unbalanced ROLE WITH AN ATOM: ​ Neutrons help stabilize the nucleus of an atom ​ An atom is stable when it has an even number of protons and an even number of neutrons RADIOACTIVE DECAY: ​ Radioactive decay is the process where an unstable atom is attempting to become stable. ​ Different type of decays: ○​ alpha decay(a) ○​ beta + decay(β+) ○​ beta - Decay(β–) ○​ Gamma (γ) ​ Alpha Decay: Also known as Helium 4 when the unstable atom has too many protons in the nucleus. ​ An atom undergoing Alpha decay will lose 4 amu(atomic mass) and 2 protons. Example: Sc-45 (21 protons) will become Potassium-41 (19 protons) ​ Beta +: Also known as Positron happens when the nucleus has too many neutrons. An atom undergoing Beta plus decay will end up losing a proton. Example: Oxygen-17 (8 protons) will end up being Nitrogen-17 (7 protons) ​ Beta- : Also known as an electron happens when the ratio of protons to neutrons is high. An atom undergoing Beta minus will gain a proton Example: Oxygen-17 (8 protons) will become Fluorine-17 (9 protons) ​ Yamma: Causes an atom to go from an “Excited State” to ground state. Does not change the element just removes the “*”  ​ Half-Life: Rate of radioactive decay -​ Formula: Total time/Half-Time ​ Example: The half-life of Zn-71 is 2.4. If one had 100mg at the beginning, how many grams would be left after 7.4 minutes elapsed Total time/Half-time= 7.4minutes/2.4minutes is 3 minutes. 100mg->50->25->12.5. 12.5mg would be left after 3 half-lives STELLAR NUCLEOSYNTHESIS ​ Nuclear fusion is the process by which new atomic nuclei (elements) are created from pre-existing nucleons (protons and neutrons) and nuclei ​ Nucleosynthesis is specifically energy that refers to the fusion processes that occur within stars to form various elements Conditions Necessary Fusion: ​ Extremely high….. 1.​ Temperature 2.​ Pressure 3.​ Density Conditions Created? ​ Gravity’s compression of matter….. ○​ generates immense heat ○​ Increases pressure ○​ Allows for nuclei to come closer together Nuclear Binding Energy is… the amount of energy required to break a nucleus apart into its constituent protons and neutrons. (breaking part neutron and protons to make energy) Summary: ​ In nuclear fusion, the energy released is directly related to the mass defect, which is essentially the difference in nuclear binding energies.  ​ The Proton-Proton Chain is… ○​ A type of hydrogen fusion that takes place in the star’s core. ○​ Converts hydrogen to helium, releasing energy as a byproduct. ○​ Process that applies to small main-sequence stars. ​ The energy comes from the difference in the nuclear binding energies of the reactants (starting substances) and our products (ending substance) nucleus…....individual protons + individual neutrons Catalyst: ​ In stellar nucleosynthesis, a catalyst is something that is used to make processes faster or more efficient without depleting, or completely using up what something…. ○​ In case, the CNO are the catalyst that are replenished by end of the nuclear reactions The Alpha Process: ​ Aka alpha capture or the alpha ladder ​ One of 2 types of nuclear fusion reactions by which stars convert helium to heavier elements ​ Electrons are found outside of the nucleus in the orbitals  ​ Star cycle ○​ Main sequence; hydrogen fuses to helium; spending 90% of their lifetime ○​ Fusion is the process within stars where nuclear fusion reactions take place, resulting in hydrogen, carbon, oxygen and iron ○​ Nuclear fusion is the process where two or more atomic nuclei come close enough for the strong nuclear force to overcome the electromagnetic force between the protons, fusing or combining the nuclei into a heavier nucleus BOHR MODELS: ​ Period is a horizontal row of chemical elements on the periodic table ​ Core electrons are electrons tightly bound to the nucleus. # of protons in the nucleus, minus the number of valence electrons ​ Valence electrons are the electrons in the outermost shell. The # of valence electrons is equal to the column # the element is found in ​ A group/family is a vertical column on the periodic table ○​ Sulfur is in group 16 and in period 3 ​ Hydrogen and Helium do not have core electrons because they both only have one shell ​ Helium does NOT have 8 valence electrons despite being in group 8A because it only has 2 protons which means if it were to have more valence electrons it would automatically make it a negatively charged element, making it unstable ​ The furthest away from the nucleus has the most energy and the closest to the nucleus has the least energy ENERGY STATES: ​ Electromagnetic spectrum- is a wavelength spectrum that communicates how we visualize light in our world. ​ Visible light- is how humans perceive light on the electromagnetic spectrum which is measured in nanometers and wavelengths. ​ A photon- is waves of energy expelled from or inserted into an atom via some sort of reaction or transfer. ○​ Ground state….. THE ATOMIC SPECTRA: ​ Atomic Spectra- A visual representation of the electromagnetic radiation emitted or absorbed by an electron during transitions between different energy levels in an atom. 1)​ Continuous Spectrum / The Spectrum ​ C for colors of the rainbow ​ Full atomic spectra- no lines-all the colors of rainbow wavelengths ​ Caused by dense/hot objects 2)​ Emission Spectra/bright line spectrum ​ E for emission ​ Colored lines shown throughout a black spectra ​ Happens when electrons release energy and go back to ground state ​ Excited electrons go back to ground state 3)​ Absorption Spectrum/dark line spectrum  ​ A for absorption (color missing) ​ Black lines on a continuous spectrum ​ Happens when electrons absorb energy and go to the excited state PROPERTIES AND CHANGES IN MATTER: ​ Chemical Properties of Matter are… Characteristics of matter that can only be measured or observed when the substance interacts with another substance; chemical changes are irreversible; they change identity/color ​ Toxicity can be harmful/deadly to certain organisms ​ Flammability is the ability to be burned and continue the burn while being exposed in air ​ Corrosivity is when a substance is able to eat/erode another substance ​ Reactivity is how a substance will react to another substance and possibly create something new ​ Indicators of Chemical Change ○​ Color change​​ ○​ Density ○​ Magnetism ​ Indicators of Physical Change ○​ Transparency - Light can pass through the substance ○​ Malleability - Able to be reshaped with enough force ○​ Conductivity - Able to transmit heat or electricity from point A to B ​ Intensive Properties stay the same and do not change no matter how much of it.  ​ Extensive Properties are changes depending on the amount of matter: ○​ Odor change ○​ Changes in energy ○​ Solid disappearance ○​ Gas formation ○​ Precipitation formation ​ Physical properties of matter are characteristics of matter that can be measured and observed without changing its identity of the substance: ○​ Color ○​ Odor ○​ Texture ○​ Melting point ○​ Boiling point ○​ Mass ○​ Weight METALS, METALLOIDS AND NONMETALS ​ Metals ○​ Malleable ○​ Ductile ○​ Conduct electricity and heat well ○​ Mostly solid ○​ Have luster ​ Nonmetals ○​ Brittle ○​ Poor conductors ○​ Can be solid, liquid or gas ○​ NOT malleable, conductive nor ductile ​ Semimetals AKA metalloids ○​ Luster ○​ Semi-conductive ○​ NOT malleable, durable nor ductile PERIODIC TRENDS: ​ Atomic Radius is… ​ The total distance from the nucleus of an atom to the outermost orbital of its electron. Used to estimate the size of an atom. ​ Measured in picometers (pm). 1pm = 1 x 10^-12m ​ Atomic radius increases from right to left within a period Cation & Anion ​ CATION: An atom that loses one or more electrons to form an ion with a positive charge. ​ ANION: Atom that gains one or more electrons to form an ion w/ a negative charge ​ Cations are smaller than their parent atoms, and anions are larger Ionization Energy ​ Energy required to remove the outermost electron from the ground state of a gas atom. ​ The size of an atom affects its ionization energy. ​ The closer an electron is to the nucleus, the more energy required to remove it. Electron Affinity ​ Energy change that happens when an atom gains an electron. ​ An atom with higher electron affinity will release a larger amount of energy.