Honors Chem Midterm

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the science that deals with the materials of the universe and the changes these materials undergo
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Terms in this set (86)
the science that deals with the materials of the universe and the changes these materials undergo
What is chemistry?
1. Make an observation (state a problem and collect data)
2. Formulate a hypothesis
3. perform an experiment
What are the steps of the scientific method?
anything that has mass and occupies space
What is matter?
Elements are only one type of atom where compounds are different atoms of different elements in fixed combinations.
What is the difference between elements and compounds?
tiny particles called atoms
What does matter consist of?
A physical property can be observed without changing the substance. A chemical property explains the ability of the substances to change into different substances
What is the difference between a physical and chemical property?
chemical: Wood burning, rusting of steel

physical: color, odor, state of matter, volume, density, melting/boiling point
What is an example of a chemical change? Physical?
a physical change does not affect the composition of the substance. A chemical change changes one substance into a new substance (chemical reaction)
What is the difference between a physical and chemical change?
Physical: change of state, stick breaking (can be reversible or irreversible)

Chemical: Rusting, burning, decomposing, synthesizing and fermenting
What are examples of a physical change? Chemical?
a MIXTURE of metals
What is an alloy?
air, chicken noodle soup, alloysWhat are examples of mixtures?variable compositionMixtures contain?not uniform throughout, separated through filtrationWhat is a heterogeneous mixture and how can it be separated?sand in water, chicken noodle soupWhat are examples of a heterogeneous mixture?uniform throughout, also known as a solution, seperate through distillationWhat is a homogeneous mixture and how can it be separated?uses different boiling points to separate the componentsWhat is distillation?air, salt dissolved in waterWhat are examples of a homogeneous mixture?always the same composition, pure elements or compounds, only one type of atom or moleculeWhat are pure substances?A mixture contains multiple types of atoms where a pure substance is only one type of atomWhat is the difference between a mixture and pure substance?1. Elements are made of tiny particles called elements 2. all atoms of a given element are identical 3. Atoms of a given element differ from those of another element 4. Atoms of different elements can combine to form compounds 5. Atoms are indivisible in chemical processesWhat are the elements of Dalton's atomic theory?a distinct substance composed of the atoms of 2 or more elements and always contains the same relative masses of those elementsWhat is a compound?the number of atoms of that elementWhat does a formula for a compound represent?1. atoms of any element could be made to emit tiny negative particles 2. This lead to the discovery of the electron 3. Atoms also must contain positive particles because atoms are neutrally chargedWhat did JJ Thomson discover using the cathode ray tube (1)?JJ ThomsonWhat scientist is contributed with the plum pudding model?Gold Foil Experiment which disproved plum pudding modelWhat experiment did Ernest Rutherford (2) do?That since some of the alpha particles were bounced straight back at him, he concluded there must be a center of concentrated positive charge in an atom. Also the nuclear atomWhat did Rutherford conclude?nucleus is small and dense and positively charged. It contains protons and neutronsWhat is the nuclear atom?1. The atom is mostly empty space 2. Most of its mass is in the nucleus 3. Most of its space/volume is outside nucleus where the electrons are foundWhat is the modern atomic theory?the electronsWhat are responsible for chemical behavior?neutron (neutral), proton (+), and electron (-)What are the 3 types of subatomic particles?the number of protonsWhat identifies the element?amuWhat is atomic mass measured in?different versions of the atoms of elements. They contain different number of neutrons but same number of protons and electronsWhat is an isotope?tells you the number of protons in an atom of that element, must also equal the number of electronsWhat is the atomic number?# of protons + # of neutronsHow do you find mass number?increasing atomic mass and arranged families with similar chemical propertiesHow did Mendeleev arrange the first periodic table?by increasing atomic numberHow is the modern periodic table arranged?Vertical columns, elements share similar chemical propertiesWhat are groups in the periodic table?are horizontal rows, indicate highest energy level in the atomWhat are periods on the periodic table?never contain single atoms, they are bonded in pairsWhat are Diatomic particles?H2, N2, F2, O2, I2, Cl2 and Br2What are the 7 diatomic particles?1.they carry a charge 2. Are formed by a neutral atom losing or gaining electrons 3. share the electron configuration of a noble gasWhat are ions?cations (+) and anions(-)What are the types of ions?1. + charge 2. formed by atom losing electrons 3. metals form positive ions by losing their valance electronsWhat are cations?1. - charge 2. Formed by gaining electrons 3. Nonmetals form negative ions by gaining enough electrons to get a set of 8 valance electronsWhat are anions?1. composed of a positive and negative ion 2. electrically neutral 3. most are crystalline solids at room temp 4. Have high melting points 5. Can conduct electricity when melted/dissolved in water 6. Coordination number- the number of ions of opposite charge that surround an ion in a crystleWhat are the properties of ionic compounds?1. Nuclear model- small dense nucleus with positive charge and protons and neutrons, most of the atom's mass 2. remainder of the atom contains the electrons, mostly empty space, most of the atom's volumeWhat was Rutherford's model of the atom?x-rays, visible light, microwavesWhat are examples of electromagnetic radiation?in waves, but also in a stream of tiny packets of energy called photonsHow does light travel?inversely proportionalwavelength and frequency are?higher frequency, smaller wavelength, blue, violet and greenWhat is higher energy radiation?lower frequency, longer wavelength, red, orange and yellowWhat is lower energy radiation?they become excited and jump to higher energy levels. To return to ground state they must release the same amount of energy in the form of light (a photon)What happens when atoms absorb energy? How do they return back to ground state?whatever amount of energy is absorbedWhat is a quantum?quanizedEnergy levels of atoms are?1. same set of discrete energy levels for atoms of the same element 2. unique to that element 3. Atomic Emission Spectrum- no 2 elements have the sameWhat does quantized mean?1. Nucleus surrounded by quantized energy levels where electrons are located 2. Electrons move in fixed circular orbits around nucleusWhat is the Bohr model of the atom?Wave Mechanical ModelWhat is another name for the Quantum Mechanical Model?orbitalWhat are regions of space where you are most likely to locate an electron?cannot know an electron's precise position, only a probability of locating in a particular region in spaceWhat is Schrodinger?1. Principal energy levels 2. Sublevels 3. OrbitalsHow are orbitals organized?the first way orbitals are organized. labeled with whole numbers (1-7), highest number means farther from nucleusWhat are principal energy levels?whole number and s,p, d or fHow are sublevels labeled?electron configurationsThe ways in which electrons are arranged in various orbitals around the nuclei of atoms1. Aufbau Principle 2. Pauli Exclusion Principle 3. Hund's RuleWhat are the 3 rules of electron configuration?electrons occupy the orbitals of the lowest energy level firstWhat is the Aufbau principle?an atomic orbital may contain at most 2 electrons and to occupy the same orbital the electrons must have an opposite spinWhat is the pauli exclusion principle?one electron enters each orbital until all the orbitals contain 1 electron with the same spin directionwhat is hund's rule?1. Atomic Size 2. Electronegativity 3. Ionization EnergyWhat are the 3 periodic trends?atomic radiusWhat is atomic size measured in?increases from top to bottom, decreases from left to rightWhat does atomic size do from top to bottom on the periodic table? left to right?the ability of an atom of an element to attract electrons when the atom is in a compoundWhat is electronegativity?decrease from top to bottom, increase from left to rightWhat does electronegativity do from top to bottom? left to right?FluorineWhat is the most electronegative element?the energy required to remove an electron from an atomWhat is ionization energy?decreases from top to bottom, increases from left to rightWhat does ionization energy do from top to bottom? left to right?Theoryset of tested hypotheses that gives an overall explanation of some part of naturean observation is something that is witnessed and can be recorded. A theory is a possible explanation of why nature behaves in a particular wayWhat is the difference between a observation and theory?it has mass, and it occupies spaceWhat are the characteristics of matter?elements of the universeWhat do we call the 100 different atoms?moleculemade up of atoms that are stuck togetherdifferent elementsA compound always contains atoms of?Solid- is rigid and has a fixed shape and volume, Liquid- has a definite volume but takes the shape of its container, Gas- has no fixed volume or shapeWhat are the 3 states of matter and describe them?a compound contains only particles of identical atomic composition. A mixture is a collection of compounds or elements that are present in varying amounts.What is the difference between a compound and a mixture?elements or compoundsPure substances are either?solutionA homogeneous mixture is also called a?