Normal Size Small Size show me how
QOA science final
|a liquid mixture in which particles can be seen and easily separated by filtration or settling
|How is a solute different then a solvent in a solution?
|the solute is present in a smaller amount
|Weak tea is an example of
|How can a scientist safely tell whether an unknown solution is salt or sugar in water?
|by testing the electrical conductivity
|when you add so much solute that no more dissolves
|What is one way to increase the solubility of sugar in water?
|heat the water
|How would a solute affect the boiling point of water?
|the water will boil at a higher temperature
|When a solute is added to a solvent, the freezing point of the solution is
|lower than the freezing point of either substance alone
|What is characteristic property of acids?
|turn blue litmus paper red
|Acids are described as corrosive because they
|"eat away" at other materials
|Acids naturally present in food are safe to eat because they usually are
|You can find the pH of a substance by using
|a mixture containing particles that are too small to be seen easily but are large enough to scatter a light beam is called a
|Neutralization is a reaction between
|acid and a base
|What does a neutralization reaction produce?
|breaks down complex molecules of food into smaller particles
|What is the difference between chemical digestion and mechanical digestion?
|chemical digestion requires enzymes
|How is pH important during digestion?
|different enzymes work best at different pH values
|Normal rainfall is slightly acidic, which means its pH must be
|between 5 and 7
|When a solid compound dissolves in water,
|each of its particles becomes surrounded by water molecules
|a measure of how well a solute can dissolve in a solvent at a given temperature
|a substance that is present in a solution in a smaller amount and is dissolved by the solvent
|What are factors that affect the solubility if a solvent?
|pressure, the type of solvent, and temperature
|What are the characteristic properties of bases and acids?
|Acids: taste sour, react with metals and carbonates, and turns blue litmus paper red Bases: tastes bitter, feels slippery, and turns red litmus paper blue
|what is the product of a neutralization?
|reaction between an acid and a base.
|part of the solution that is present in the largest amount
|a mixture that has only a little solute dissolved in a certain amount of solvent.
|mixture containing small, undissolved particles that do not settle out.
|one that has a lot of solute dissolved in the solvent
|when you can continue to dissolve more solute
|example of a colloid:
|Which can conduct an electric current salt water or sugar water?
|What happens when an ionic solid mixes with water?
|water molecules surround each particle.
|What happens when a molecular solid mixes with water?
|the solute breaks down and into individual molecules
|what happens to the solute's particles whenever a solution forms?
|They leave each other and become surrounded by particles of the solvent.
|How do you measure the concentration of a solution?
|you compare the amount of solute to the amount of the solvent
|Which is more soluble in water, baking soda or sugar?
|The higher the pressure of the gas, the________gas can dissolve in a solvent.
|Extra info about acids and bases:
|1. most solids become more soluble as the temperature goes up 2.most gases become less soluble as the temperature goes up 3. Carbon Dioxide dissolves better in cold water than in hot water.
|What is neutral, acidic and basic on the pH scale?
|neutral: pH of 7 acidic:lower than pH of 7 basic: higher than the pH of 7
|Extra info about strengths of acids and bases:
|1. a strong base produces more OH- ions than a weak base 2.a strong acid produces more H+ ions than a weak acid
|an enzyme that helps break down the starchy carbs into smaller sugar molecules
|Amylase works best when the pH is near
|Where does the most chemical digestion take place?
|Carbon is able to bond with atoms of other elements in many different ways because it has
|four valence electrons
|An element whose atoms can make straight chains, branched chains an rings is
|Which form of pure carbon is so hard that it can be used in cutting tools?
|Which form of pure carbon is formed of layers that slide past one another?
|what is another name for carbon compounds?
|Starch is an example of a
|What can tell you about methane(CH4)from its molecular formula?
|it contains four hydrogen atoms
|Which compounds have the same molecular formula but different structures?
|Which class of organic compounds stores the most energy, gram for gram?
|lipids or fats
|A substituted hydrocarbon that contains one or more hydroxyl groups is called an
|Substances that provide the energy and raw materials that the body needs are
|Which term describes the breaking down of polymers, such as starch or proteins, into monomers the body can use
|Proteins are nutrients used in the body mostly for
|building and repairing body parts:)
|What factor determines the primary differences among living things
|the order if nucleotides in their DNA
|What nutrients needed by the human body are NOT organic compounds?
|A carbohydrate is made up of the elements carbon and hydrogen, plus
|What is the maximum possible number of hydrogen atoms on a carbon chain called?
|Compounds that contain only the elements carbon and hydrogen are called
|What property do all hydrocarbons have?
|they burn easily
|What shapes do hydrocarbons NOT form?
|What is a property of many organic liquids?
|they have strong odors
|What is the shape of pure carbon fullerenes?
|hollow ball with a pattern like a geodesic dome
|How many chemical bonds can each carbon atom form?
|a very large organic molecule made up of chains of small molecules
|The classes of organic compounds found in all living things are
|halogen compounds, alcohols, organic acids, and esters.
|The simplest kind of carbohydrate is
|true or false: Your body can digest starch, but another common complex carbohydrate, cellulose, passes through your body undigested
|What are polymers called that are produced in factories instead of by living things called?
|What are amino acids?
|building blocks that make up proteins
|elements needed by the human body
|What is lead mostly made of?
|Do organic compounds conduct electrical currents?
|What are hydrocarbons only made of?
|carbon and hydrogen
|Carbon atoms can bond with other__________and with atoms of other elements in many different ways.
|a molecule with an atom of another elements carbon and hydrogen
|a compound that contains carbon
|the compound that results when an alcohol and an organic acid are chemically combined
|very large molecule made of many smaller molecules bonded together
|the smaller molecules that make up a polymer
|a compound containing only the elements carbon and hydrogen
|a substituted hydrocarbon with one or more hydroxyl groups
|the smaller molecules that make up polymers
|a substituted hydrocarbon with one or more carboxyl groups
|What are the properties of carbon?
|mix poorly with water and are flammable
|compounds that have the same chemical formula but different structual formulas.
|A hydrocarbon in which all the bonds between carbon atoms are single bonds
|a hydrocarbon in which one or more of the bonds bewtween carbon atoms is double or triple
|atoms of other elements replace one or more hydrogen atoms in a hydrocarbon.
|What are the three ways carbon atoms bond to form the backbones for molecules?
|straight, ring, chain
|Why can the element carbon exist in different forms?
|it can bond in a lot of other ways
|crystal, hard, used for jems and cutting stone
|ring shaped, soft, slippery, used for pencils and lubricants
|hollow sphere, enclose an open area, possibly carries medicines through the body
|long, hollow tube, extremely strong, conductors in electronic devices
|How does a diamond form?
|under heat and alot of pressure
|Why are many organic compounds liquid or gas at room temperature?
|they have low melting points and low boiling points
|What are the names of the 3 hydrocarbons that have molecules made of chains of carbon atoms?
|methane, propane, ethane
|What does a structural fromula show about a molecule of a compound?
|kind, number, and arrangement of atoms in a molecule.
|Each dash in a structural fromula represents a chemical
|singles bonds, ends in -ane example:ethane
|double or triple bonds, ends in -ene or -yne, example: ethene
|example of synthetic polymer:
|synthetic polymers that can be molded or shaped
|they combine 2 or more substances in a new material with different properties
|____________is a synthetic composite made of glass fibers and liquid plastic
|What are the four classes of polymers found in all living things?
|carbs, lipids, PROTEIN :), nucleic acids
|Why is glucose sometimes called "blood sugar"?
|the body circulates glucose to all body parts to blood.
|a large chainlike molecule made of simple carbs
|polymers formed from smaller molecules called amino acids
|When an object's distance from another object is changing,
|it is in motion
|The basic SI unit of length is the
|Speed equals distance divided by
|When you know both the speed and direction of an object's motion, you know the
|You can show the motion of an object on a line graph in which you plot distance agaist
|The steepness of a line on a graph is called the
|On an acceleration graph showing speed versus time, a straight line shows the acceleration is
|If you know a car travled 300 kilometers in 3 hours, you can find its
|The rate at which velocity changes is called
|If the spped of an object does NOT change, the object is traveling at a
|Changing direction is an example of a kind of
|Average SPeed is
|the total distance traveled divided bt the total time
|If an object moves in the same direction and at a constant speed for 4 hours, what is true?
|the objects's velocity did not change
|A place or object used for comparision to determine if something is in motion is called
|a reference point
|On a graph showing distance versus time, a horizontal line represents an object that is
|not moving at all
|The SI is used
|all over the world
|If you know the distance an object has traveled in a certain amount of time, you can determine
|the acceleration of the object
|Motion is measured realtive to a
|the rate at which and object is moving at a given instant time.
|speed in a given direction
|A straight diagonal line on a distance-verus-time graph indicates_________speed
|A horizontal line on a distance versus time graph mean that an object
|is at constant speed
|What is the SI unit for velocity
|meter per second per second
|What does a straight line mean on a speed versus time graph?
|The SI unit for speed is
|The formula for speed is
|A rider finshes a 10-km bicycle trip in 2 hours. The average speed of the rider is
|A velocity tells
|speed and direction
|A runner starts a 5 km race at 10:15 am. She finsihes at 10:45. With this info you can calculate the runners
|You can calculate the slope of a graph line by
|dividing rise over run
|The rate at which velocity changes is
|To find a objects acceleration, you need to know its starting speed, its starting speed, its ending speed, and
|Speed versus time graph
|a straight line is constant and a slanted line means the object is accelerating at a constant speed
|Distance versus time graph:
|a curved line means that the object is accelerating
|What is an example of exerting force?
|answers may very. ex: a carpenter hammering a nail
|What happens when two forces act in the same direction?
|They add together
|The tendency of an object to resist change in its motion is known as
|The greater the mass of an object to resist change in its motion is known as
|the greater its inertia
|The force of gravity on a person or object on the surface of a planet is called
|One way to increase acceleration is by
|The force that one surface exerts on another when the 2 rub together is called
|What is an example of rolling friction
|bike tires on the road as you ride
|When the only force acting on a falling object is gravity, the object is said to be in
|Air resistance is a type of
|The force of gravity on a person or an object at the surface of the planet is known as
|The law of universal gravitation states that any 2 objects in the universe, with out exception,
|attract each other
|Forces can be added together only if they are
|acting on the same object
|The product of an objects mass and velocity is called its
|According to the law of conservation of momentum, when 2 objects collide in the absence of friction,
|momentum is not lost
|The achievement of lifting a rocket off the ground and into space can be explained by
|Newton's 3rd law
|What is required for a rocket to lift off into space?
|thrust that is greater than Earth's gravity
|An object that travels around another object in space is called
|Any force that causes an object to move into a circle is called
|In physical science, a push or a pull, is called a
|The momentum of an object is in the same direction as its
|How can you increase the momentum if an object?
|by increasing its mass
|The amount of matter in an object is called its
|What is an example of increasing friction intentionally?
|throwing sand on an icy driveway
|The force that pulls falling objects through air experience a type of friction called
|According to Newton's 3rd law of motion, when a hammer strikes and exerts force on a nail, the nail
|exerts equal force back onto the hammer
|The SI unit for force is the
|Balanced forces acting on an object
|never change the objects motion
|The total momentum of a group of objects is conserved unless
|outside forces act on the objects
|t or f: Unbalanced forces do not change an objects motion
|Newton's first law of motion:
|an object at rest will remain at rest and an object moving at a constant velocity will continue moving at a constant velocity, unless acted upon by an unbalanced force
|Newton's second law of motion:
|acceleration depends on the objects mass and net force acting on the object
|Newton's third law of motion:
|if one object exerts a force on another object, then the second object exerts a force of equal strength in the opposite direction on the first object.
|law of conservation of momentum:
|in the absence of outside forces, the total momentum of objects that interact does not change
|the friction that acts on objects that are not moving
|occurs when 2 solid surface slide over each other
|occurs when an object rolls across a surface
|occurs when a solid object moves through fluid
|What does friction depend on?
|types of surfaces and how hard the surfaces push together
|What is the SI unit for momentum?
|A force is described by
|its strength and direction
|When the forces acting on an object are balanced the net force of the object is
|in the opposite direction as motion
|The amount of gravity between objects depends on their masses ans the
|distance between them
|A__________causes an objects motion to change
|What law says that forces come in pairs?
|What affect the gravitational attraction?
|mass and distance
|The unit of force,newton, is equal to
|Snowshoes enable a person to walk on deep snow because
|increase the area over which the persons weight is distributed
|a unit of pressure is called a
|Air pressure exerted equally in an object from different directions is
|Why doesn't pressure crush you?
|pressure inside your body balances the air pressure outside ur body
|Air pressure decreases as
|Water pressure increases as
|Which type of substance does Pascals priciple deal with
|One application of pascals principle is
|a hydraulic car lift
|Plastic bottle when squeezed...which principle?
|What does a hydraulic system do?
|What direction does a bouyant force act in?
|If an object floats, the volume of displaced water is equal to the volume of
|the portion of the object that is submerged
|What scientific rule states that the buoyant force on an object is equal to the weight of the fluid displaced by the object?
|Smoke rises up a chimney because of
|Bernoulli's principle helps explain
|The mass per unit of volume of a substance is its
|Pressure can be measured in
|newtons per square meter
|Which scientific rule states that the pressure exerted by a moving stream of fluid is less that than the pressure of the surrounding fluid?