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79 terms

Physical Science Final

For the 9th grade MPCS science final
STUDY
PLAY
A substance that is made up of only one kind of atom is an
element
Which of the following statements about ice melting is true?
water molecules move from their fixed positions
the phase change in which a substance changes from a solid to a liquid is
melting
the phase change in which a substance change from a solid to a gas or vapor without changing to a liquid first is
sublimation
which of the following phase changes is an endothermic change
vaporization
which of the following phase changes is an exothermic change
deposition
the Greek philosopher Democritus coined what word for a tiny piece of matter that cannot be divided
atom
J.J. Thomson's experiments provided evidence that an atom
contains negatively charged particles
The number of protons in one atom of an element is that element's
atomic number
to find the number of neutrons in an atom, you would subtract
atomic number from the mass number
Which statement is true about oxygen-17 and oxygen-18
they are isotopes of oxygen
what can you assume has happened if an electron moves to a higher energy level?
the electron has gained energy
which statement accurately represents the arrangement of electrons in Bohr's atomic model
electrons travel around the nucleus in fixed energy levels with energies that vary from level to level
what does the electron cloud model describe
the most likely locations of electrons in atoms
which statement about electrons and atomic orbitals is true?
an electron cloud represents all the orbitals in an atom
the glowing of a neon light is caused by electrons emitting energy as they
move from higher to lower energy levels
mendelev arranged the known chemical elements in a table according to increasing
mass
which statement is true about the metalloid silicon
silicon is a better conductor of an electric current than sulfur is
at room temperature none of the metals are
gases
atoms of the most reactive elements tend to have
one or seven electrons
an alkali metal has one valence electron, while an alkaline earth metal has
two
among the alkali metals, the tendency to react with other substances
increases from top to bottom within the group
which of the following gases emit colors when an electric current is applied
helium and neon
to keep them from reacting, some highly reactive elements are stored in
argon
the formation of an ionic bond involves the
transfer of electrons
which of the following statements correctly describes the substance with the formula KI
there is a one-to-one ratio of potassium ions to iodide ions
in the compound MgCl2, the subscript 2 indicates that
there are two chloride ions for each magnesium ion
the water molecule H2O is polar because it contains two polar single bonds and
its molecule has a bent shape
water has a higher boiling point than expected because
of the strong attractions between polar water molecules
the elements most likely to form more than one type of ion are the
transition metals
beryllium, Be, and chlorine, Cl, form a binary ionic compound with a one-to-two ratio of beryllium ions to chloride ions. the formula is
...
a force acting on an object does no work if
the force is not in the direction of the object's motion
if you exert a force of 10 N to lift a box a distance of .75m, how much work do you do?
7.5J
the SI unit of power is the
Watt
a machine is a device that can multiply
force
how can you make the work output of a machine greater than the work input?
you can't!
reducing friction in a machine
increases its efficiency
a mechanical device requires 400J of work to do 340J of work in lifting a crate. What is the efficiency of the device?
85%
an inclined plane reduces the effort force by
increasing the distance over which the force is applied
an ax is an example of a
wedge
the ideal mechanical advantage of a pulley system is equal to the
number of rope segments supporting the load
an example of a compound machine is a
bicycle
an element has a fixed composition because it contains only one type of
atom
the symbol for elements have either ____ or ___ letters
one/two
in a ________ mixture, the parts of the mixture are noticeably different from one another
heterogeneous
if a spoon gets hot quickly when it is used to stir a pot of soup, it is probably made of
metal
_____ is a process that could be used to separate dissolved particles from the liquid in a solution
distillation
when a metal changes color because it has been heated a _______ change has occurred
physical
when a metal changes color because it has reacted with another substance, a _______ change occurred
chemical
the ______ theory of matter states that all particles of matter are in constant motion
Kinetic
______ between particles of a gas and the walls of the container cause pressure in a closed container of gas
collisions
a graph representing Charles's law shows that the _______ of a gas increases at the same rate as the ______ of the gas
volume/temperature
water boils when its vapor pressure becomes equal to -________ pressure
atmospheric
during vaporization, a substance changes from a ______ to a _______
liquid to a gas
neutrons and ______ have almost the same mass
protons
if element Q has 11 protons, its atomic _____ is 11
number
the ___________ of an isotope is the sum of the protons and neutrons in the nucleus
mass number
In Bohr's model of the atom, _______ move in a fixed orbit around the nucleus
electrons
when all the electrons in an atom are in orbitals with the lowest possible energy, the atom is in its ______ state
ground
Mendelev's periodic table was useful because it enabled scientists to predict properties of unknown ______
elements
the atomic mass unit(amu) is defined as one-twelfth the mass of a _____-12 atom
Carbon
from left to right across a period in the periodic table, elements become less _____ and more ________ in their properties
metallic; nonmetallic
in general, a _______ metal will be more reactive than an alkaline earth metal in the same period
alkali
the two most reactive groups of elements in the periodic table are the alkali metals and the ________
halogens
although they are called _____ lights, they can contain any noble gas
neon
in an ionic compound the attractions between cations and _____ hold the compound together
...
in its simplest form, the alloy brass consists of zinc and ______
copper
to produce stainless steel, ______ is added to iron
chromium
any part of a force that does not act in the direction of an object's motion does no _____ on an object
work
the SI unit of work is the _____
jule
you calculate work by multiplying the force acting in the direction of _______ by the distance the object moves
motion
the ideal mechanical advantage of a third-class lever is always ___ than one
less
two or more simple machines working together make up a ____ machine
compound
a watch consists of a complex system of gears. each gear acts as a continuous _____
lever
which of the following has the highest viscosity
corn syrup
a substance has a melting point of 0C and a boiling point of 100C. the substance is most likely
water
a material that is malleable and conducts electricity is most likely
a metal
which of the following is a physical change/
sawing a piece of wood in half
a substance that has high reactivity
easily combines chemically with other substances