CHEM 104 Final Exam (Hill) | Questions & Answers (100 %Score) Latest Updated
2024/2025 Comprehensive Questions A+ Graded Answers | With Expert Solutions
Is air a mixture or a pure substance? - Mixture
Mixture - a physical combination of two or more substances present in variable amounts
Composition of Air - 78% Nitrogen, 21% Oxygen, 1% Argon and CO2
Air Particles unchanged by respiration? - Nitrogen and Argon
Air Particles changed by respiration? - Oxygen and CO2
Name 5 kinds of Air Pollutants - Carbon Monoxide, Ozone, Sulfur Dioxide, Nitrogen Dioxide, Particulate
Matter (dust, sand)
Ozone Molecule - O3
Ozone Pollutant - Smelly gas that can cause breathing problems
Air Quality Index - Scale that ranks levels of ozone and other air pollutants (0-500) 500=high
Air Quality index for Healthy-Moderate Air - 0-100
Atom - Smallest particle of an element
Molecule - A group of atoms bonded together
Classification of pure substances - Elements and Compounds
,Compounds - 2 or more elements chemically combined; Completely the same chemical combination
throughout
Elements - A molecule composed of one kind of atom; cannot be broken into simpler units by chemical
reactions
Inventor of Periodic Table - Mendeleev
What does an element's group tell us? - Group is the vertical column. Tells us how many valence
electrons are in the outer shell; tells us how reactive the element is
Hydrocarbons - Organic molecules consisting of only carbon and hydrogen. Have different prefixes than
other molecules used for fuels
Pneumonic for Hydrocarbon prefixed - Mother Eats Peanut Butter
Methane, Ethane, Propane, Cyclopropane
Combustion - Rapid reaction between oxygen and fuel that results in heat and light
PPH to PPM conversion - Move decimal four places to the right
Types of Mixtures - Heterogenous and Homogenous
Heterogenous Mixture - Mixture with uneven distribution of different substances; not the same
throughout
Homogenous Mixture - Mixture in which the composition is uniform throughout
, What do periods mean on the Periodic Table? - How many valence shells there are
Protons - Positively charged particles inside nucleus
Neutrons - Neutrally charged particles inside nucleus
Electrons - Negatively charged particles outside nucleus
To be electronically stable, an atom must have an equal number of ___ and ___ - Protons and Neutrons
What does the Atomic number tell you? - Number of protons in the nucleus. Always equal to the
number of electrons (if stable)
Alkali Metals Properties - Highly reactive metals
Halogens Properties - Reactive non-metals
Noble Gases Properties - Un-reactive nonmetals
Isotope - Atoms of the same element that have different numbers of neutrons
Mass Number - Sum of the number of neutrons and protons in an atomic nucleus; tells you the isotopes
How to get number of neutrons using the Periodic Table? - Subtract atomic number from the mass
number
Valence Electrons - The electrons in the outermost shell of an atom; these are the electrons involved in
forming bonds
Covalent Bond - sharing a pair of electrons between atoms
2024/2025 Comprehensive Questions A+ Graded Answers | With Expert Solutions
Is air a mixture or a pure substance? - Mixture
Mixture - a physical combination of two or more substances present in variable amounts
Composition of Air - 78% Nitrogen, 21% Oxygen, 1% Argon and CO2
Air Particles unchanged by respiration? - Nitrogen and Argon
Air Particles changed by respiration? - Oxygen and CO2
Name 5 kinds of Air Pollutants - Carbon Monoxide, Ozone, Sulfur Dioxide, Nitrogen Dioxide, Particulate
Matter (dust, sand)
Ozone Molecule - O3
Ozone Pollutant - Smelly gas that can cause breathing problems
Air Quality Index - Scale that ranks levels of ozone and other air pollutants (0-500) 500=high
Air Quality index for Healthy-Moderate Air - 0-100
Atom - Smallest particle of an element
Molecule - A group of atoms bonded together
Classification of pure substances - Elements and Compounds
,Compounds - 2 or more elements chemically combined; Completely the same chemical combination
throughout
Elements - A molecule composed of one kind of atom; cannot be broken into simpler units by chemical
reactions
Inventor of Periodic Table - Mendeleev
What does an element's group tell us? - Group is the vertical column. Tells us how many valence
electrons are in the outer shell; tells us how reactive the element is
Hydrocarbons - Organic molecules consisting of only carbon and hydrogen. Have different prefixes than
other molecules used for fuels
Pneumonic for Hydrocarbon prefixed - Mother Eats Peanut Butter
Methane, Ethane, Propane, Cyclopropane
Combustion - Rapid reaction between oxygen and fuel that results in heat and light
PPH to PPM conversion - Move decimal four places to the right
Types of Mixtures - Heterogenous and Homogenous
Heterogenous Mixture - Mixture with uneven distribution of different substances; not the same
throughout
Homogenous Mixture - Mixture in which the composition is uniform throughout
, What do periods mean on the Periodic Table? - How many valence shells there are
Protons - Positively charged particles inside nucleus
Neutrons - Neutrally charged particles inside nucleus
Electrons - Negatively charged particles outside nucleus
To be electronically stable, an atom must have an equal number of ___ and ___ - Protons and Neutrons
What does the Atomic number tell you? - Number of protons in the nucleus. Always equal to the
number of electrons (if stable)
Alkali Metals Properties - Highly reactive metals
Halogens Properties - Reactive non-metals
Noble Gases Properties - Un-reactive nonmetals
Isotope - Atoms of the same element that have different numbers of neutrons
Mass Number - Sum of the number of neutrons and protons in an atomic nucleus; tells you the isotopes
How to get number of neutrons using the Periodic Table? - Subtract atomic number from the mass
number
Valence Electrons - The electrons in the outermost shell of an atom; these are the electrons involved in
forming bonds
Covalent Bond - sharing a pair of electrons between atoms
