ISCI 2002 FINAL EXAM
Hertz
1 vibration per second = 1 ___
Element
An _____ is any material that consists of only one type of atom.
B
An object is pulled northward with a force of 10 N and southward with a force of 15 N. The magnitude of the net force on the object is A) 0 N. B) 5 N. C) 10 N. D) 15 N.
negative ion
Atom gaining one or more electrons
positive ion
Atom losing one or more electrons
Atoms
Basic unit of matter
Wavelength
Distance between the same point on successive waves
A
E) none of the above Which direction does a table push a book resting on it? A) up B) left C) right D) down
identical
Electrons are ______
First Law of Thermodynamics
Energy cannot be created or destroyed.
positively negatively
Every atom is composed of a ____ charged nucleus that contains protons and surrounded by _____ charged electrons.
B
If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by about A) 5 m/s. B) 10 m/s. C) 15 m/s. D) a variable amount E) depends on its initial speed
increases
Increasing the concentration increases the number of collisions per second and therefore ____ the rate of the reaction.
1800
Protons are about ____ times as massive as electrons.
same
Protons have the ____ quantity of charge as electrons.
atoms
The charging of bodies relates to the structure of ______.
B
The statement, "There are regions beneath Earth's crust that will always be beyond the reach of scientific investigation," is a A) fact. B) speculation. C) hypothesis. D) scientific statement. E) theory.
115 90
To date, ____ distinct kinds of atoms are known—____ are found in nature, and the rest are synthesized.
shorter
Waves with higher frequencies have _____ wavelengths
thermal expansion
When the temperature of a substance is increased, its particles jiggle faster and move farther apart.
Compounds
___ have properties uniquely different from the elements from which they are made.
Energy
___ produces changes in matter.
Vibrations
_____ make waves
Wave motion
_________ requires an energy source and a medium (except for light) through which the energy is transferred.
activation energy (Ea)
__________ is the minimum energy required to overcome the initial breaking of bonds in reactants.
physical change
a change in the physical properties of a substance.
machine
a device for multiplying force or changing the direction of force.
thermometer
an instrument that measures temperature by comparing the expansion and contraction of a liquid as it gains or loses thermal energy.
Electric conductors
are materials that allow charged particles to pass through them easily
Electric insulators
are materials that have tightly bound electrons.
Electric force
can attract some objects and repel others.
Protons
carry a positive charge
physical property
describes the look or feel of a substance.
chemical property
describes the tendency of a substance to transform into a new substance.
repel
electrons _____ the electrons of neighboring atoms.
electrical repulsion
electrons have _______ _______ that prevents atomic closeness.
reaction rate
how quickly the concentration of reactants decreases and how quickly the concentration of products increases.
higher frequency
increased rate of energy transfer
Fundamental rule for electricity
like charges repel, unlike charges attract
infrared thermometer
measures temperature by the radiation a substance emits.
Atom
the fundamental unit of an element.
Frequency
the number of complete wavelengths that pass a point in a given time
atomic number
the number of protons in each element listed in the periodic table.
Wave motion
the propagation of a disturbance through a medium
Power
the rate at which energy is changed from one form into another.
molecular polarity
If the polar bonds in a molecule are facing in equal and opposite directions, the polarity may cancel out.
endothermic reaction
In an ________ _______ there is a net absorption of energy. Energy from the environment is stored in chemical bonds, reaction can get colder
exothermic reaction
In an ____________ ____ there is a net release of energy. Temperature of the reaction increases, light is produced, etc.
Period
Inverse of wavelength
field lines
Lines coming from an object representing the strength of the force. The denser the lines, the stronger the force.
Compound
a substance that consists of atoms of different elements.
conservation
is defined in everyday language as "to save"—in physics, to "remain unchanged."
kinetic energy
is the energy of a moving body mechanical, thermal, electrical, sound, light, nuclear
Electric Charge
is the fundamental quantity that underlies all electric phenomena. •comes in two kinds: positive and negative
Temperature
is the measure of hotness or coldness of an object (degrees Celsius, or degrees Fahrenheit, or kelvins).
Potential Energy (PE)
stored energy due to position, shape, or state. In its stored state, energy has the potential for doing work. - elastic, gravitational, chemical
Law of Conservation of Energy
the absence of external work input or output, the energy of a system remains unchanged.
Radiation
the process by which thermal energy is transferred by electromagnetic waves.
An electric field
the space that surrounds any charged object
work
- is defined as the product of the force exerted on an object and the distance the object moves (in the same direction as the force). - is done only when a force succeeds in moving the body it acts upon.
c
A kilogram is a measure of an object's A) weight. B) force. C) mass. D) gravity. E) center of mass.
Entropy
A measure of disorder or randomness.
C
Disregarding air resistance, objects fall at constant A) velocity. B) speed. C) acceleration. D) distances each successive second.
chemical reaction
During a __________, one or more new compounds are formed as a result of the rearrangement of atoms.
Kinetic Theory of Matter
Matter is made up of tiny particles (atoms or molecules) that are always in motion.
Law of Mass Conservation
No atoms are gained or lost during any reaction.
A
One object has twice as much mass as another object, and also has twice as much A) inertia. B) velocity. C) gravitational acceleration. D) volume. E) all of the above
C
One-half second after starting from rest, a freely falling object will have a speed of about A) 20 m/s. B) 10 m/s. C) 5 m/s. D) 2.5 m/s. E) none of the above
physical contact
Reactant molecules have to make _____ _____ with each other in order to transform into products.
Concentration Temperature Catalysts
Reaction rates are affected by:
medium
The ___ transporting the wave returns to its initial condition after the disturbance has passed.
work
The _____ done on the object is the average force multiplied by the distance through which the object is moved.
elemental formula
The _______ _______used to show the proportion by which atoms combine to form an element.
Conduction
The direct transfer of heat from one substance to another substance that it is touching.
2nd law of thermodynamics
The principle whereby every energy transfer or transformation increases the entropy of the universe. Ordered forms of energy are at least partly converted to heat, and in spontaneous reactions, the free energy of the system also decreases.
B
The scientific method is a method for A) making hypotheses. B) gaining new knowledge. C) making observations. D) testing theories. E) designing experiments.
D
The synthesis of a large collection of information that contains well-tested and verified hypotheses about certain aspects of the world is known as a scientific A) fact. B) hypothesis. C) law or principle. D) theory. E) none of the above
Atom
The term _____ is used when discussing the submicroscopic.
Element
The term _____ is used when referring to macroscopic quantities.
Period
The time it takes for a complete vibration
thermal energy
The total energy (kinetic and potential) of the submicroscopic particles that make up a substance.
Convection
The transfer of thermal energy by the circulation or movement of a liquid or gas
C
Which has the greatest density? A) 1 kg of feathers B) 10 kg of feathers C) 1 kg of lead
Reactants
____ must be moving fast enough (have sufficient kinetic energy) to overcome the energy of activation.
chemical change (chemical reaction)
a change in which one or more substances are converted into different substances
heat
a flow of thermal energy due to a temperature difference.
Element
a material made of only one kind of atom.
Element
a material made of only one kind of atom. For example, pure gold is an element because it is made of only gold atoms.
Power
a measure of how quickly work is done