Summative Test Long Quiz #3 in Science PDF

Chemistry, the Particle Nature of Matter What is Chemistry? -​ It is a branch of Science that deals with the study of Matter; its properties, composition, characteristics, structural changes, and the energy released during such changes. The 5 Branches of Chemistry -​...

Chemistry, the Particle Nature of Matter What is Chemistry? -​ It is a branch of Science that deals with the study of Matter; its properties, composition, characteristics, structural changes, and the energy released during such changes. The 5 Branches of Chemistry -​ Organic Chemistry -​ The study of carbon and its compounds; the study of the chemistry of life -​ Inorganic Chemistry -​ The study of compounds not covered by organic chemistry; the study of inorganic compounds, or compounds that don’t contain a C-H bond. -​ Analytical Chemistry -​ The study of the chemistry of matter and the development of tools to measure the properties of matter -​ Physical Chemistry -​ The branch of chemistry that applies physics to the study of chemistry commonly includes applying thermodynamics and quantum mechanics to chemistry. -​ Biochemistry -​ The study of chemical processes that occur inside living organisms Matter -​ Is anything that takes up space and has mass -​ The word Matter comes from the Latin Word “Materia”, meaning “material” or “stuff” -​ The only thing that wouldn’t be matter would be energy. -​ No mass nor volume so they can’t be matter! Physical Properties of Matter -​ Physical Property -​ Is the property that can be observed without changing the identity of the substance.  -​ Viscosity -​ Its resistance to flow. -​ Conductivity -​ Is a material’s ability to allow heat to flow. -​ Malleability -​ The substance’s ability to be hammered into a thin sheet -​ Melting and Boiling Point -​ Are the temperatures at which a solid becomes a liquid and a liquid becomes a gas. -​ Density -​ Is the ratio of it’s mass compared to its volume. -​ Solubility -​ The ability to dissolve in another substance. -​ Ways to increase solubility: Heating, Grinding or Smashing, and Stiring Two Common Separation Points -​ Filtration -​ Process that separates materials based on the size of their particles based on the size of their particles -​ Distillation -​ The process that separates the substances in a solution based on their boiling points Observable Physical Properties -​ Malleability -​ The substance’s ability to be hammered into a thin sheet -​ Color -​ The color of an object can be seen and is a physical property of matter. -​ Odor -​ The smell or odor an object gives off can also help identify a substance. -​ Conductivity -​ Is a material’s ability to allow heat to flow.  -​ Metals are usually the best conductors of heat and electricity. -​ Insulation -​ When an object passes heat and electricity poorly. -​ Ductility -​ The ability to be drawn or pulled into a wire -​ Magnetism -​ The attraction to a magnet -​ Texture -​ The visual and tactile quality of a surface -​ Relative Density -​ The density of an object compared to its surrounding material. Measurable Properties of Matter -​ Properties that must be measured with a tool -​ Mass -​ The amount of matter in an object or substance -​ Using a triple beam balancence or a scale for calculation -​ In science, always use grams or kilograms as units. -​ Weight -​ Measure of the pull of gravity on an object. -​ Different gravity, different weight. -​ Volume -​ The amount of space an object takes up. -​ Measured differently for regular solids, irregular solids, and liquids. -​ Ex. of Reg. Solids: any solid you can measure the length, width, and height of. (LxWxH) -​ Ex. of Irregular Solids: Any solid you can measure —------ -​ Ex. of Liquids: any object that has a shape but does have a definite volume. -​ To calculate this, the use of a graduated cylinder to find the volume at the meniscus -​ Must read to the bottom of the curve (MENISCUS) -​ Unit is milliliters or Liters Chemical Properties of Matter -​ This is the property of matter that describes a substance based on its ability to change into a new substance with different properties. -​ Can be observed with your senses. -​ Are not as easy to observe as physical properties -​ Is any chemical property is any ability to produce a change in the composition of matter -​ Flammability -​ Material’s ability to burn in the presence of oxygen -​ Reactivity -​ How readily a substance combines chemically with other substances The 5 Physical States of Matter 1.​ Bose-Einstein Condensate -​ Exists at extremely cold temperatures (ABSOLUTE 0) which are achieved by scientists in labs -​ Particles are locked together so firmly that they move as a single unit -​ The densest of the 5 (It just like me fr)  2.​ Solids -​ The particles are tightly compact -​ Particles vibrate without the ability to move freely -​ Definite shape and volume 3.​ Liquid -​ Particles are compact but are able to move around close to each other -​ No definite shape but has a definite volume. 4.​ Gas -​ Particles can easily spread out or move close together -​ Particles move freely and with a lot of energy -​ No definite shape or volume 5.​ Plasma -​ Exists at extremely high temperatures (several MILLION degrees Celsius) -​ Particles are broken apart -​ Particles move freely and with extremely high energy -​ The form is not too common on Earth, but out there in the universe, it is the most common form of matter -​ Examples: Lightning, Fluorescent and Neon Lights, Aurora Borealis Properties of Matter pt.2 -​ Chem. Property of Matter -​ Describes a substance based on its ability to change into a new substance with different properties -​ Can be observed with your senses, but not as easily as physical properties -​ Objects are changed into entirely new substances with different properties -​ Changes in Matter -​ If Matter = changed state or appearance without altering the composition, then it’s a Physical Change -​ Else, they’re Chemical Change -​ During chemical change, the atoms that are present rearrange into new molecules, but all of the original atoms are still present Rusting -​ The iron atoms in the nail combine with oxygen atoms from O2 in the air to make a new substance, rust, with a different composition Signs of Chemical Change 1.​ Odor Production - this is an odor far different from what it should smell like (ex. Rotting Eggs, Decomposing Flesh) 2.​ Change in Temperature -​ Exothermic - When Energy is released during the chemical change -​ Endothermic - When energy is absorbed causing a decrease in temperature of the reactant material 3.​ Change in Color - Like when a Fruit Ripens yk 4.​ Formation of Bubbles - this can indicate the presence of a gas. Bubbles produced when boiling water is not a chemical change. 5.​ Formation of a precipitate - When two liquids are combined and a solid is produced. Kinetic Molecular Theory -​ Possess energy of motion that is dependent on the temperature -​ As the temperature increases, the atoms and molecules gain more energy which will make them more excited Classification of Matter by Composition -​ Pure Substances -​ Matter whose composition does not change from one sample from another -​ Made from a single type of atom or molecule -​ All samples have the same characteristics -​ Mixture -​ Matter whose composition may vary from one sample to another -​ To or more types of atoms or molecules combined in variable proportions -​ Because composition varies, different samples have different characteristics. -​ Elements -​ Pure substances that can’t be decomposed into simpler substances by chemical reactions -​ Decomposed = Broken down -​ Basic Building blocks of matter -​ Composed of a single type of atom -​ Though those atoms may or may not be combined into molecules. -​ Compound -​ Pure substances that can be decomposed -​ Chemical combinations of elements -​ Composed of molecules that contain two or more different kinds of atoms -​ All molecules are identical, so all samples of a compound behave the same way -​ Heterogenous -​ A mixture that does NOT have a uniform composition throughout -​ Connatins regions within the sample with different characteristics -​ Atoms or molecules not mixed uniformly. -​ Homogenous -​ A mixture that HAS a uniform composition throughout -​ Every piece of a sample has identical characteristics, though another sample with the same components may have different characteristics. PHASE CHANGE -​ Intermolecular Forces -​ Within all matter, there is a constant competition between temperature and intermolecular forces. -​ When temperature wins, molecules fly apart and you have GAS  -​ When intermolecular forces win, molecules clump tightly together, resulting in a SOLID. -​ Melting and Boiling -​ Melting Point is the temperature at which a substance changes from a solid to a liquid -​ Boiling Point is = Temperature where Liquid becomes Gas  -​ Energy -​ Is the ability to do work or cause change -​ Is what changes a phase of matter -​ Kinetic Energy -​ When it is in motion : -​ Particles with a lot of kinetic energy move far and far apart (GAS) -​ Particles with little kinetic energy move slowly & close together (SOLID) -​ Temperature -​ Is the Average Kinetic energy of the individual particles in a substance Changes of State -​ Changes of state are physical arranges in matter. -​ They are either reversible or irreversible changes that do not involve changes in matter’s chemical make up or chemical properties What happens during a phase change or change of state? -​ During a phase change, heat is either absorbed or released -​ Heat energy is released as molecules slow down and move closer together -​ Heat energy is absorbed as molecules speed up and expand Energy, Temperature, and Changes of State -​ Energy is always involved in changes of state. Matter either loses or absorbs energy when it changes from one state to another. -​ The amount of energy in matter can be measured with a thermometer. -​ Melting -​ The change from the solid state to liquid state is melting -​ Molecules speed up, move farther apart, and absorb heat energy. -​ Freezing -​ The change from liquid to solid is called Freezing. -​ Molecules slow down, move closer together, and release heat energy. -​ Energy is released (decreasing) during freezing. -​ Vaporization -​ Phase change from a liquid to gas. It occurs att the boiling point of a matter -​ Molecules speed up, move farther apart, and absorb heat energy -​ Two types of vaporization -​ Boiling is when vaporization takes place below the surface of a liquid -​ Evaporating is when vaporization takes place at the surface of a liquid. -​ Evaporation -​ This occurs at temperatures below the boiling point, explaining how puddles dry up. -​ It takes more than speed for water molecules to escape the liquid state. -​ During evaporation, these faster molecules also must be near the surface, heading in the right direction, and they must avoid hitting other water molecules as they leave. -​ Condensation -​ Molecules slow down, move closer together, and release heat energy. -​ This process, which is the opposite of vaporization, is called Condensation. -​ This occurs when a gas loses enough thermal energy to become liquid. -​ Condensation and Vaporization are opposites  -​ Sublimation -​ Some substances can change from solid state to a gas state without ever becoming a liquid. -​ During this process, known as sublimation, the surface particles of the solid absorb enough energy to become a gas. -​ Molecules speed up, move farther apart, and absorb heat energy. -​ Wait a minute, is this the feeling of Deja vu? -​ Deposition -​ Deposition moving directly from a gas to a solid state. -​ Molecules slow down, move closer together and release heat energy. -​ HISTORY OF ATOMIC THEORY LEUCIPPUS & DEMOCRITUS (450 BCE) ​ Ancient Greek philosophers who first proposed the idea that all matter is composed of small, indivisible units called atomos. However, this was just a philosophical concept at the time. JOHN DALTON (1803) ​ Postulates of Dalton’s Atomic Theory a.​ Elements are made of tiny particles called atoms.  b.​ Atoms of one element are identical while atoms of different elements are different. c.​ In a chemical reaction, atoms change the way they are bound to other atoms, but the atoms themselves are unchanged. JOSEPH JOHN THOMSON (1904) ​ Discovered the electron in 1897 through his cathode ray tube experiments. ​ Proposed the Plum Pudding Model of Atom. ERNEST RUHTERFORS (1911) ​ Positive charge is concentrated in the nucleus as shown in the Gold Foil (Alpha Particle) experiment ​ Atom is mostly composed of empty space. ​ Discovered proton ​ James Chadwick - lead scientist who discovered neutron. ​ Fundamental Charge of Proton: 1.6022 x 10^-19 C ​ Mass of Proton: 1.67x10^-27 g ​ Mass of Neutron: 1.68x10^-24 g HENRY MOSELEY (1914) ​ Each element has a unique atomic number based on the number of protons. ​ Leads to modern numbering of the periodic table based on atomic number rather than weight. ATOMIC MODELS JOHN DALTON - 1766-1844 ​ British chemist and physicist ​ Proposed the Solid Sphere Model in the early 19th century ​ Shifted from philosophical ideas to scientific theory ​ First atomic model based on experimental evidence and quantitative observations ​ EVIDENCES ○​ Law of Conservation of Mass – By Antoine Lavoisier, this law states that mass is neither created nor destroyed in a chemical reaction. ○​ Law of Definite Proportion – By Joseph Proust, this law states that a given pure chemical compound always contains the same elements in the same fixed mass ratio. ○​ Law of Chemical Combination – By John Dalton, this law states that elements combine in small, whole-number ratios to form compounds ​ BILLIARD BALL MODEL (ATOMIC THEORY 1803) ○​ STRENGTH - First to depict atoms as indivisible and indestructible basic units of matter and are all made up of same material. ○​ Limitations  ​ Could not explain differences in atomic mass within an element (isotopes) ​ Did not account for the presence of subatomic particles like protons, neutrons, and electrons ​ Could not explain the behavior of atoms in chemical reactions JJ THOMSON (1856-1940) ​ English physicist known for his work on the nature of electrons ​ Proposed the Plum Pudding Model in the late 19th to early 20th century ​ Discovered electrons as distinct particles ​ Shifted understanding from indivisible atom to subatomic particles ​ EVIDENCES ○​ Cathode Ray Experiments - By measuring the heat generated by the cathode rays on a metal plate, Thomson showed the rays were made of particles, which he called 'corpuscles' (now known as electrons). ​ PLUM PUDDING MODEL 1904 ○​ STRENGTH - According to this theory, atoms are like plum pudding, with tiny positive charges scattered throughout a cloud of negative electrons. This theory helped explain why atoms have a neutral charge overall and why they emit light when they collide with each other. ○​ LIMITATIONS ​ Could not explain why electrons don't collapse into the positive sphere ​ Failed to predict the distribution and arrangement of electrons ​ Lacked explanation for the nucleus and its positive charge ERNEST RUTHERFORD (1871-1937) ​ New Zealand-born physicist known for his contributions to nuclear physics ​ Introduced the Nuclear Model in the early 20th century ​ First model to propose a central, massive nucleus ​ Explained the behavior of positively charged alpha particles in the gold foil experiment ​ James Chadwick – the lead scientist who discovered NEUTRON. ​ EVIDENCES  ○​ Gold Foil Experiment - In this 1909 experiment, Rutherford bombarded a thin gold foil with alpha particles. He found a small fraction of particles were deflected at large angles, contrary to expectations if the mass was evenly distributed. This suggested a dense, charged nucleus. ​ NUCLEAR MODEL 1911 ○​ STRENGTH - According to this theory, atoms have a nucleus with a positive charge and most of the mass, surrounded by electrons that orbit like planets. It explains why particles can pass through or bounce off atoms, and is the basis of our current understanding of atomic structure. ○​ LIMITATIONS - ​ Did not explain the stability of the nucleus against electrostatic repulsion ​ Lacked details about electron orbits and energy levels ​ Did not incorporate the principles of quantum mechanics NIELS BOHR (1885-1962) ​ Danish physicist known for his pioneering work in atomic structure ​ Proposed the Planetary Model in the early 20th century ​ Explained atomic spectra with precision ​ Introduced the concept of quantized energy levels ​ EVIDENCES ○​ Quantized orbits - Like planets orbiting the Sun, electrons can only occupy discrete circular orbits around the nucleus at specific distances. This agreed with atomic emission spectra. ○​ Atomic Emission Spectra – When atoms are heated or electrically excited, their electrons can jump to higher energy levels further from the nucleus. ​ PLANETARY MODEL 1913 ○​ STRENGTH ​ According to this theory, electrons orbit the nucleus of an atom in specific energy levels or shells. This theory helped explain why atoms emit light and why they absorb certain colors of light. It also helped explain the stability of atoms and why they don't fall apart. ○​ LIMITATIONS ​ Limited to explaining the hydrogen atom  ​ Couldn't account for the behavior of multi-electron atoms ​ Didn't incorporate the wave-like nature of electrons ERWIN SCHRODINGER AND WERNER HEISENBERG (1887-1961) ​ Austrian physicist renowned for his contributions to quantum mechanics ​ Proposed the Quantum Model in the 1920s ​ Quantum mechanics provides a comprehensive understanding of electron behavior ​ Schrödinger's model successfully explains multi-electron atoms ​ Quantum mechanics is the foundation of modern atomic theory ​ EVIDENCES ○​ Quantum spin - Electrons have quantized intrinsic angular momentum. ○​ Electron diffraction - Wave-like diffraction patterns demonstrate quantum wave-particle duality of electrons ​ WAVE MECHANICAL MODEL 1920S ○​ STRENGTH - According to this theory, electrons exist as a probable wave-like pattern around the nucleus, not in a specific orbit. It explains why electrons act like particles and waves, and is the foundation of our understanding of atomic structure and widely used in modern physics. ○​ LIMITATIONS ​ Mathematical complexity of the model ​ Requires advanced mathematics to calculate electron probabilities ​ Doesn't provide a simple visual representation of atomic structure ISOTOPES ​ Atoms that have same atomic number but different atomic mass. ​ The protons and neutrons are referred as nucleons ​ Example of isotopes ○​ Carbon 14 - It is most famously used in radiocarbon dating to determine the age of archaeological and geological samples ○​ Cobalt 60 - The gamma rays can be precisely targeted to destroy tumors while minimizing damage to healthy tissue.  ○​ Calcium 47 - A radioactive isotope of calcium that serves as a tracer for studying calcium uptake in plants and bone metabolism in medicine ○​ Chromium 51 - Used to label red blood cells to examine circulation, detect gastrointestinal bleeding, and study diseases like anemia. ○​ Iodine 131 - It concentrates in the thyroid gland and is used to image and track thyroid function, helping diagnose hyperthyroidism and other thyroid diseases. ○​ Copper 67 - Used to diagnose and track cancer due to its accumulation in tumor cells. TYPES OF ISOTOPES ​ STABLE ISOTOPES - NOn-radioactive and foes undergo decay ​ RADIOISOTOPES - Unstable element emits radiation Different isotopes can exist, and these can be identified by its respective mass number. Mass number is the sum of the number of protons and the number of neutrons in an atom. History of the Periodic Table of Elements JOHANN WOLFGANG DOBEREINER ​ Developed “triads”, group of three (3) elements with similar properties. LAW OF TRIADS ​ Elements with similar chemical properties often groups of three, where the atomic weight of the middle element is roughly the average of the other two.  ○​ Lithium, Sodium, and Potassium ○​ Calcium, Strontium, and Barium ○​ Chlorine, Bromine, and Iodine JOHN ALEXANDER REINA NEWLANDS -​ Observed similarities between the first and ninth elements, the second and the tenth elements, etc. Proposed the Law of Octaves. -​ LAW OF OCTAVES - The elements in increasing order of atomic mass and noticed that every eighth element exhibited similar properties. Unfortunately, there were some elements that were missing, and the law did not seem to hold for elements that were heavier than calcium. DMITRI MENDELEEV -​ The Father of Modern Periodic Table of Elements -​ Produced a table based on atomic weights but arranged 'periodically' with elements with similar properties under each other PERIODIC LAW -​ The physical and chemical properties of an elements are a periodic function of their atomic masses. -​ Gaps were left for elements that were unknown at that time and their properties predicted (the elements were gallium, scandium, and germanium) -​ The order of elements was re-arranged if their properties dictated it. -​ Periods – also known as series are the horizontal rows in the periodic table. -​ Groups – also known as families are the vertical columns HENRY MOSELY -​ He modified the 'Periodic Law' to read that the properties of the elements vary periodically with their atomic numbers. IUPAC -​ International Union of Pure and Applied Chemistry  -​ Responsible for the ongoing governance and standardization of the periodic table. GROUPS vs PERIODS QUANTUM MECHANICAL MODEL OF THE ATOM ELECTRON SHELLS -​ Electrons occupied several energy levels. The principal energy level/energy levels or electron shells are represented by a positive number from 1-7. This can be seen on the number of periods in the periodic -​ There are several types of orbitals that can occur in an energy level. These orbitals have a specific shape and are represented by a lowercase letter such as the: s, p, d, f. ORBITALS -​ Region of space which there is a high probability of finding electron. Each orbital can hold up to two (2)electrons. ENERGY LEVELS -​ Corresponding to a shape where electron is likely to be found. -​ -​ ELECTRONIC CONFIGURATION -​ Electron configuration describes the arrangement of electrons in an atom. -​ Electrons occupy specific energy levels (shells) around the nucleus. -​ Each energy level has a designated capacity for electrons. -​ Subshells (s, p, d, f) exist within each energy level, further defining electron placement THREE RULES OF ELECTRON CONFIGURATION THE AUFBAU PRINCIPLE -​ Electrons fill energy levels in a specific order following the Aufbau principle. -​ Lower energy levels fill up before higher ones. THE PAULI EXCLUSION PRINCIPLE -​ A maximum of two electrons may occupy a single orbital. Each orbital can hold TWO electrons with opposite spins. HUND’S RULE -​ If two or more orbitals of equal energy are available, electrons will occupy them singly with the same spin, before filling them in pairs with opposite spins. -​ Within a sublevel, place one e- per orbital before pairing them. -​ “Empty bus seat rule” QUANTUM NUMBERS ​ Quantum numbers are a set of numbers that describethe properties of electronsin an atom. ​ They are used to define the energy levels and orbitals in which electrons reside FOUR QUANTUM NUMBERS  1.​ PRINCIPAL QUANTUM NUMBER (n) ○​ The principal quantum number (n) represents the main energy level or shell n which an electron resides. ○​ It can have values of 1, 2, 3, 4, and so on. ○​ Higher values of n correspond to higher energy levels and greater average distance from the nucleus. 2.​ AZIMUTHAL QUANTUM NUMBER (l) ○​ The azimuthal quantum number (l) describes the shape or type of orbital within a given energy level. ○​ It can have values ranging from 0 to (n - 1). ○​ The values of l are represented by letters: s (l = 0), p (l = 1), d (l = 2), f (l = 3), and so on. 3.​ Magnetic Quantum Number (ml) ○​ Describes the orientation of an orbital within a subshell. ○​ Values: Ranges from -l to +l, including 0. ○​ Each subshell has a specific number of orbitals with different orientations. 4.​ SPIN QUANTUM NUMBER (ms) ○​ Represents the intrinsic spin of the electron (like a tiny spinning sphere). ○​ Values: Only two possibilities: +½ (clockwise) or -1/2 (counterclockwise) PERIOD VS. GROUP OCTET RULES ​ States that elements gain or lose electrons to attain an electron configuration of the nearest noble gas, to become stable. Metallic Character and Reactivity ​ Metals tend to be good conductors, malleable, and ductile. Metallic character and reactivity generally decrease across a period and increases down a group. It is the ability of element to share e-. ELECTRONEGATIVITY ​ A measure of the tendency of an atom to attract a bonding pair of electrons. Generally, it increases from left to right across a period. This is because atoms on the right side have fewer valence electrons (electrons in the outermost shell) and a stronger attraction for electrons. IONIZATION ENERGY ​ Measures the tendency of a neutral atom to resist the loss of electrons. It increases from left to right, while decreases down the group. Like electronegativity, the increased distance between the nucleus and valence electrons in lower groups makes it easier to remove an electron