Earth and Physical Science Flashcards
Mass
Is the quantity of matter something possesses, and usually has a unit of weight associated with it.
Matter:
commonly defined as anything that takes up space and has mass.
what two types of change can matter undergo?
Chemical and Physical
Chemical Change:
occurs when an original substance is transformed into a new substance with different properties. An example would be the burning of wood, which produces as and smoke.
Physical change
Transformation that do not produce new substances, such as stretching a rubber band or melting ice.
What are the fundamental properties which we use to measure matter?
mass, weight, volume, density, and specific gravity
Extrinsic:
properties are directly related to the amount of material being measured, such as weight and volume…
Intrinsic
properties are those which are independent of the quantity of matter present, such as density and specific gravity.
Atom
the ultimate particle of matter:
smallest particle of an element that still is a part of that element.
Center of an atom is called?
Nucleus
Nucleus is made up of what two particles?
positively-charged particle called proton
and particle that has no charge called neutron
The nucleus of an atom is surrounded by negatively-charged particles called?
Electrons.
Molecular Weight
a Mole is the amount of substance that contains 6.02 X 10(23) basic particles.
What is atomic weight?
The weight of one mole of an element.
How is the the atomic weight or mass of the atom figured?
by the total number of protons and neutrons in the atom’s nucleus.
What is an element?
a substance which cannot be broken down by chemical means, composed of atoms that have the same atomic number and are defined by the number of protons and neutrons they have. In general the elements increase in mass from left to right and from top to bottom on the periodic table.
Isotope
element having one or more form. example carbon
approximately how many elements are there?
109 known elements
88 of these occurs naturally on earth while the other are synthesized
Hydrogen
the most abundant element in the universe.
Helium
is the second most abundant element.
Earth is composed mostly of what?
iron, oxygen, silicon, and magnesium.
90% human’s body mass consists of oxygen,carbon,hydrogen, nitrogen, calcium, and phosphorus.
75% of elements are metals
11 are gasses in their natural state
molecule
smallest part of a substance that isn’t chemically bonded to another atom.
Chemical formulas
used to represent the atomic composition of a molecule.
ex. H2O
Compounds
substances that contain more than one type of element.
What are compounds that are made up of molecules which are all identical called?
pure substances.
mixture
consists of two or more substance that are not chemically bonded. mixtures are generally placed into two categories: homogeneous, heterogeneous
Homogeneous Mixture
Components that make up the mixture are uniformly distributed; ex are water and air
Heterogeneous Mixture
components of the mixture are not uniform;they sometimes have localized regions with different properties. ex. the different components of soup make it a heterogeneous mixture. Rocks as well are not uniform and have localized regions with different properties.
Solution
a uniform or homogenous mixture of different molecules
If the solution is a liquid, the material being dissolved is called what?
Solute
The liquid that a solute is being dissolved in is called what?
Solvent
Saturated
reached a point of maximum concentration, in it no more solute will dissolved
States of Matter are usually grouped into what 3 main categories
solids, liquids, gases
Solids
Rigid: they maintain their shape and have strong intermolecular forces. Typical solids are rigid at room temperature. In solids the molecules are closely packed together, and solid materials usually have a high density. In the majority of solids, called crystalline solids, the ions or molecules are packed into crystal structure that is highly ordered.
Liquids
cannot maintain their own shape, confirm to their containers, and contain forces strong enough to keep molecules from dispersing into spaces. Solids will generally become liquids when heated to a high enough temperature.
Gases
Have indefinite shape; disperse rapidly through space due to random movement and are able to occupy any volume. They are held together by weak forces. Gases are produced when liquids are heated enough, and have an additional energy associated with them called the enthalpy of vaporization. this is the energy required to break the liquid bonds, and allow the material to transfer to the gaseous phase.
What are two specific states of matter?
liquid crystals -which can maintain their shape as well as be made to flow
Plasmas-gases in which electrons are stripped from their nuclei
four properties of gases related to each other are?
- Volume of the gas
- Pressure of the gas
- Temperature of the gas
- The number of the gas molecules
3 laws that relate to gases are?
Boyle’s law- the volume of a given number of gas at a constant temperature is inversely proportional to pressure. In other words; if the initial volume decreases by half, the pressure will double and vice versa. equation is P1V1=P2V2
Charle’s law-the volume of a given amount of gas at a constant pressure is directly proportional to absolute (Kelvin) temperature. If the temperature of the gas increases, the volume of the gas also increases and vice versa. The representative equation is V1/T1=V2/T2.
Avogadro’s law- Equal volumes of all gases under identical conditions of pressure and temperature contain the same number of molecules. The molar volume of all ideal gases at 0*C and pressure of 1atm. is 22.4 liters.
Kinetic theory of gases
assumes that gas molecule are very small compared to the distance between the molecules. Gas molecules are in constant, random motion;they frequently collide with each other and with the walls of whatever container they are in.
Ideal gas law
is an important equation that is used to estimate the properties of gas at different temperatures and pressures. Called the ideal gas law because in order to be effective, the gas much be ideal, meaning:
1. the gas consists of a large number of molecule that move randomly.
2. the volume that the molecules of the gas occupies is very small compared to the to the total volume of the gas.
3. there are no attractive or repulsive interactions between the gas molecules.
Ideal gas law can be stated as: PV= nRT
P=pressure, V =volume, n=#of mols of gas, R=ideal gas constant (8.314J/molK) and T =temperature.
Periodic Table
is a chart which arranges the chemical elements in a useful, logical manner.
elements are listed in order of increasing atomic number, lined up so that elements which exhibit similar properties are arranged in the same row or column as each other.
what does each box in the periodic table contain
each box contains the symbol of the element, its atomic number, and its atomic weight.
How do elements appear on the Periodic table?
elements appear in increasing order according to their atomic numbers except for the two separate rows.
What are the vertical columns called in the periodic table
Groups: elements within a group share several common properties and often have the same outer electron arrangement. There are two categories of groups
The main group: the number of the main group corresponds to the number of the valence electrons.
The transition elements: most of these contain 2 electrons in their valence shells
What are the horizontal rows in the periodic table called?
periods: correspond to the number of occupied electron shells of the atom.
Lanthanoids
the upper row, elements set below the main table.
Actinoids
elements set below the main table in the lower row.
What are most of the elements on the periodic table?
metals, alkali metals, alkaline earth, basic metals, transition metals, lanthanides, and actinides.
Electronic Structure of Atoms:
the electrons of an atom have fixed energy levels. Those in the principle energy levels are said to be in ELECTRON SHELLS. Shells which correspond to the highest energy levels, called VALANCE SHELLS, include the electrons usually involved in chemical bonding. Chemical formulas of simple compounds can often be predicted from valences. The valence electrons increase in number as you go across the periodic table.
The electrons in the outer orbit can combine with other atoms by giving up electrons or take on electrons. Atoms that give up electrons(CATIONS)change from being neutral to having a POSITIVE charge. Atoms that gain electrons(IONS) change from being neutral to having a negative charge. The OCTET RULE is a chemical rule which states that atoms of a low atomic number will share, gain, or lose electrons in order to fill outer electron shells with eight electrons. this is achieved through different types of bonds.
Electromagnetism
is involved in all chemical behavior, including the chemical bonds which hold atoms together to form molecules, as well as those holding molecules together to form all substances.
Electronegativity
measures the tendency of an atom to attract a bonding pair of electrons, and is affected by both the atomic number, and the distance between the valence electrons and the charged nucleus. The higher the assigned electronegativity number, the more an element or compound attracts electrons.
What are the two types of bonds formed between atoms?
Ionic
Covalent
Ionic Bond
Anions and cations, being negatively and positively charged respectively, exist because of the attraction of opposite charges.
Covalent bond
when atoms share valence electrons
Polar covalent bond
is a type of chemical bond where a pair of electrons is unequally shared between two atoms.
Metallic bond
electrons shared by two metallic atoms:
If the electronegativity values to two atoms are similar then:
metallic bonds form between two metal atoms
covalent bonds form between two non-metal atoms
Non-polar covalent bonds form when Electronegativity values are very simiular
Polar covalent bonds form when the electronegativity values are a little further apart.
Hydrogen bond
is not considered a chemical bond. Instead in a hydrogen bond, the attractive force between hydrogen is attached to an electronegative atom of one molecule and an electronegative atom of a different molecule. Usually the electronegative atom is oxygen, nitrogen,or fluorine, which have a partial negative charge. Hydrogen has the partial positive charge.
Which bonds are much weaker than both ionic and covalent bonds?
hydrogen bonds
VSEPR Bonding theory
VSEPR short for valence shell electron pair repulsion theory: a method that aids in understanding the three dimensional structure of a molecule.
What are the basics forms of molecule geometry?
Lenear-when there are 3 atoms in a molecule that have no high electronegativity differences, the molecule is linear.
Trigonal Planar- seen in molecules with four atoms that may have a lone pair on each end.
Tetrahedral- the tetrahedral molecule is the standard shape for a single central atom surround by 4 bonds. the bond angles between the different atoms may be different du to electronegativity differences.
Boiling point:
the boiling point is also the point of vaporization of a material. ex the boiling point of water is 100C at normal atmospheric pressure. Thus at 100C liquid water will turn into water vapor.
Freezing point
freeing point is also the melting point of a solid. ex. the melting/freezing point of water is 0*C.
Critical point
the critical point is the temperature and pressure at which defined stated so not exist. ex. at the critical point of water, which happens at 374*C and 218 atmospheres, there is no defined state for water. It is considrered”Plasma”,and behaves with different properties than either liquid or gas.
Latent heat
the latent heat of vaporization is the heat required for a liquid to turn into a gas.
examples: Latent heat of Vap boiling point (C)
Ethanol 855kJ/kg 78.3
Water 2260kJ/kg 100
Nitrogen 200kJ/kg -196
specific heat
the specific heat of a substance is the amount of energy it requires to raise the substance by 1 unit of temperature.
Chemical reactions
occurs when there is a conversion of one set of chemical substances to another set. Chemical reactions are cause primarily by a change in bonding structure in these substances due to the exchange of electrons.
In chemical reactions the starting substances are called?
reagents
In chemical reactions the ending substances are called?
products
2NaOH+FeSO4–>Na2SO4 +Fe(OH)2
In this reaction sodium hydroxide reacts with iron sulfate to form sodium sulfate and iron hydroxide, the products.
This is known as double displacement reaction
double displacement reaction
is when there are two reagents which interact to form two products. the IONS from both reagents are displaced, hence the name double displacement.
5 primary types of chemical reactions are?
combustion reaction, synthesis reaction, decomposition reaction,single displacement reaction,acid bas reaction
Combustion reaction
a combustion reaction occurs when oxygen is reacted in the presence of heat to a combustible compound, usually an organic compound. The products of a combustion reaction are always water and carbon dioxide. ex of a reaction of methane with oxygen will proceed as follows:
CH4+2O2–>CO2+2H2O.
Synthesis reaction
this is the most simple reaction in the book. Two compounds, usually elements, combine to form a third compound, the product:
C + O2–>CO2
Decomposition reaction
this is the opposite of a synthesis reaction, and is usually endothermic. In the decomposition reaction, a single compound decomposes to form two new compounds.
Single displacement reaction
similar to the double displacement reaction, but only one reactive species changes.
example:
MgCl2+2Na–>Mg+2NaCl
Acid Base reaction
in an acid base reaction one of two reactive species must be seen:a hydrogen ion(H+), or a hydroxide ion (OH-). Hydrogen ions are acidic in nature, and hydroxide ions are basic in nature. When combined, the two ions react to form water.
Energy States
chemical reactions are influenced by the energy state of the reagents and the products, and a chemical reaction is much more likely to occur if the energy state of the products is LOWER than the energy state of the reactiants. However, even if the energy state of the products is higher than that of the reactants, energy can be put into the chemical in order to force it to occur.
what are two primary types of reaction
Endothermic reaction and exothermic reaction
Endothermic reaction
Chemical reactions can be endothermic, meaning heat absorbing. an endothermic reaction requires an input of energy before the reaction can start. majority of chemical reactions are endothermic. ex: although air will react with metal to form rest, the reaction is endothermic in nature, and will occur either slowly or not at all.
Exothermic reaction
a chemical reaction that is exothermic, or heat releasing, will release energy during is course, forming lower energy products. These reactions are spontaneous, and do not require added energy.
Stoichiometry
is the ratio of different compounds taking part in a reaction. the reaction stoichiometry is the relative ratio of each of the reactants and products in a reaction. used to determine the amount of products that can be formed from a given set of reactants.
Acids
Naturally-occurring acid solutions, in which the solvent is always water, have several characteristic properties in common.
they have sour taste, speed up teh corrosion, or rusting, of metals;conduct electricity;and introduce H+cations into aqueous solutions.
Bases
Bases(Alkalis) don’t occur in as many common materials as do acids. a few examples are lime, lye,and soap. basic solutions, as opposed to acidic solutions have a bitter taste;conduct electricity when there solvent is water;and introduced OH- ions into an aqueous solution.
Acidity or basicity of solutions is expressed by
pH values.
pH values
a neutral solution is defined by the following: it has equal concentration of H+ cations and OH- ions, and a pH of 7. neutrality is based on the pH of pure water. The more acidic a solution, the lower is pH is a below7. the more basic the solution, the higher the pH is above 7. The pH scale is based on logarithms of base 10. ex if one solution has pH of 8 and another has a pH of 10 then there is a 10(2) or 100 fold difference between the 2.
buffer
is used to make a solution which exhibits very little change in tis pH when small amounts of an acid or base are added to it.
Acidic buffer
a solution is simply one which has a pH less than 7. Acidic buffer solutions are commonly made from a weak acid and one of its salts-often a sodium salt. A strong basic solution can be weakened by adding an acidic buffer.
Alkaline buffer
is a solution has a pH greater than 7. alkaline buffer solutions are commonly made from a weak base and one of its salts. A strong acid can be made weaker by adding an alkaline buffer.
Human body and specific pH
the human body contains many enzymes that only function at a specific pH. Once outside of this range, the enzymes are either unable to catalyze reactions or in some cases will break down. our bodies produce a buffer solution that is a mixture of carbonic acid and bicarbonate, in order to keep the pH of blood at 7.4
Catalysts
a substance that is used to increase the rate of a chemical reaction.
The rate of chemical reactions are influenced by what?
Nature of reactants- the electronegativity or electron structure of the reactants will affect how quickly they react.
Concentration of the reactants- the more concentrated a reactive species is, the more likely they will come into contact with each other and react.
Temperature: the temperature of the surrounding environment increases the internal energy of the reactants. This transfer of energy can help overcome the activation energy barrier before a reaction starts.
Activation energy
activation energy of a chemical reaction by far is the most important factor:
this is the amount of energy that needs to be put into the reaction system before the reaction can begin
Enzmes
best termed as BIOLOGICAL CATALYSTS.
are proteins found in living organisms that catalyze biological reaction.
very specific to the reaction that they work on.
created by ribosomes which bind amino acids into a long chain, know as the primary structure of an enzyme.
Physics
is the science of matter and energy, and of interactions between the two, grouped in traditional fields such as acoustics, iptics,mechanics, thermodynamics,and electromagnetism.
Motion: SPEED
is a scalar quantity and is defined as distance divided by time(ex miles per hour)
Velocity
is a vector quantity that describes speed and teh direction of travel
Magnitude of Acceleration
the change in velocity divided by the time interval.
Scalar quanity
is described only by its magnitude.
vector quanity
described by magnitude and direction
Acceleration
is change is velocity divided by time: an object accelerates not only when it speeds up, but also when slowing down or turning.
acceleration due to gravity
of a falling object near the Earth is a constant 9.8m/s2; therefore an object’s magnitude increases as it falls and decreases as it rises.
Newton’s 3 laws of motion are what?
- An object at rest will remain at rest unless acted on by an unbalanced force. an object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force. This is is often call “THE LAW OF INERTIA”
- Acceleration is produced when a force acts on a mass. The greater the mass (of the object being accelerated) the greater the amount of force needed (to accelerate the object). Think of it like this: it takes a greater amount of force to push a boulder, than it does to push a feather.
- every acton requires an equal and opposite reaction. This means that for every force, there is a reacting force both equal in size and opposite in direction. (I.e. whenever an object pushes another objet, it gets pushed back in the opposite direction with equal force.)
Denisty
an object’s density is its mass divided by its volume.
Frictional forces
arise when one object tries move over or around another;the frictional forces act in the opposite direction to oppose such a motion.
Pressure
is the force per unit area which acts upon a surface
3 important conservation laws
- Conservation of Momentum: Embodied in Newton’s first law(Law of Inertia), this reiterates that the momentum of a system is constant if no external force act upon the system.
- Conservation of Energy: Energy is neither created nor destroyed; it can be converted from one form to another(i.e. potential energy converted to kinetic energy), but the total amount of energy within the domain remains fixed.
- Conservation of angular Momentum: if the system is subjected to no external force, then the total angular momentum of a system has constant magnitude and direction. This is the common physics behind figure-skating and planetary orbits.
Potential Energy
the energy stored within an object-it has the potential to do work,.
When gravity pulls down on an object what is this called
gravitational energy
Kinetic energy
the energy of motion is the energy possessed because of an object motion.
What is the sum of an object’s kinetic and potential energies called?
Mechanical energy or internal energy
What do frictional forces convert Kinetic energy and gravitational potential energy into?
Thermal energy
Power
is the energy converted from one form to another divided by the time needed to make the conversion.
Simple Machine
is a device that alters the magnitude or direction of an applied force. ex: an inclined plane or lever
Objects that move in a curved path have acceleration towards the center of that path, what is the acceleration called?
centripetal acceleration.
Centripetal force
is the inward force causing that object to move in the curved path.
If the centripetal force is the action, the (opposite) reaction is an outwardly-directed?
Centrifugal force
Temperature
is a measure of the average kinetic energy of the atoms or molecules of a substance
Heat
is a measure of the work required to change the speeds in a collection of atoms or molecules
Calorie
is the amount of heat required to raise the temperature of 1 gram of water by 1 degree Celsius.
Specific heat
of a substance is the ratio of the amount of heat added to a substance, divided by the mass and the temperature change of the substance.
What is the change of a substance from solid to liquid or liquid to gas, etc. called?
Phase change
Heat of Fusion:
The amount of heat required to change a unit mass of a substance from solid to liquid at the melting point.
Heat of Vaporization:
The amount of heat needed to change a unit mass of a substance from liquid to vapor at the boiling point.
What are the 3 common temperature scales?
Celsius, Fahrenheit,Kelvin
The Kelvin temperature scale is also known as the what?
absolute zero(the lowest theoretical temperature possible before life ceases), the Kelvin scale is also known as the absolute scale.
water freezes at what points for Celsius, Fahrenheit,Kelvin?
Celsius: 0* C
Fahrenheit: 32*F
Kelvin 273K
What are the two mechanisms of Heat transfer
Conduction: heat transfer via conduction can occur in a substance of any phase(solid,liquid,or gas), but is mostly seen in solids.
Convection: Convection heat transfer occurs only in fluids(liquids and gases)
Both types of heat transfer are cause by molecular movement in the substance of interest.
