NES ELEMENTARY EDUCATION
SUBTEST 2
Materials that do not conduct electricity well are called_____. -
ANSWERS-insulators
In a circuit, electrons travel along a conductor in _____ loops. -
ANSWERS-closed
The word circuit means _____ - ANSWERS-circle
Magnetism - ANSWERS-A magnet is any object that has the ability to
attract ferrous objects like iron, steel, nickel, and cobalt. Magnetite,
called lodestone for many years, is a naturally occurring iron ore that
has this ability. Most permanent magnets we use are manufactured
and are a combination or alloy of aluminum, nickel, cobalt, and iron,
although none of these metals is naturally magnetic. The magnetic
field in a permanent magnet is a result of electron spin. A magnetic
field is produced by spinning electrons in an atom. Every atom is
essentially a small magnet with a north pole and a south pole. In
nonmagnetic materials, electrons spin in random directions, so the
magnetic field is not noticeable. In magnets, however, the electrons all
spin in the same direction—they are aligned—and create a north pole
and a south pole. When a bar magnet is suspended at its center by a
string, it will rotate until one end points north. That end is called the
north pole of the magnet and the end that points south is called the
south pole. In magnets, unlike poles attract, and like poles repel.
Either pole, however, can attract iron objects such as pins and paper
,clips. That is because under the influence of a nearby magnet, each
pin or paper clip becomes a temporary magnet, with its poles arranged
in a way appropriate to magnetic attraction.
_____, called lodestone for many years, is a naturally occurring iron
ore that has this ability. - ANSWERS-Magnetite
Surrounding all magnets is a region called the _____ _____. -
ANSWERS-magnetic field
Electricity and magnetism are closely _____. The movement of
electrons creates a magnetic field, so electric current creates a
magnetic field. This magnetic property can be used to make powerful
electromagnets. You can make an electromagnet by simply coiling
wire around a thin rod made of iron or steel (a nail will work, too).
When an electric current moves through the wire, it makes a magnetic
field. The strength of the magnetic flow is dependent on the number
of times the wire is coiled around the rod, and the value of the current
is dependent on the flow through the conductor. The strength of the
electromagnet becomes greater as the number of loops of wire around
the core is increased. - ANSWERS-related
Chemical energy. - ANSWERS-Energy stored in bonds of atoms and
molecules is described as chemical energy. Gasoline and coal contain
stored chemical energy.
Electrical energy. - ANSWERS-Electrical energy is produced by the
movement of electrically-charged particles (electrons). The movement
of electrons through a conductor, such as a wire, is called current (or
, circuit) electricity. Lightning is an example of a giant spark of static
electricity, or the sudden movement of electrons from a cloud to
another surface.
Heat energy. - ANSWERS-Heat energy is created by the random
movement of molecules from a warm substance to a cool substance.
Temperature, measured in degrees, is an indication of the average
kinetic energy of the moving molecules—the speed at which they
move. If the molecules in a substance move slowly, the substance has
a low temperature. If the molecules move rapidly, the substance has a
high temperature. Heat energy is transferred in three ways.
Conduction. - ANSWERS-Conduction is the process by which energy
is transferred through matter by collisions between particles. It is the
transfer of heat energy from atom to atom within a substance. As one
molecule is heated, it begins to vibrate. As it does, it passes some of
its energy to other molecules around it. Through this process, all the
molecules of an object pass energy from one to another, until they are
all hot. This is conduction. For example, a metal spoon in a cup of hot
soup becomes warmer because the molecular motion of the hot soup
molecules is transferred, via collisions, along the length of the spoon,
to the molecules in the metal spoon.
Convection. - ANSWERS-Convection is the transfer of heat in a gas
or liquid by the circulation of currents from one region to another. In
convection, the molecules get heated and rise up; the cold molecules
sink and get reheated. Then they rise again to continue the cycle. For
example, heat leaves a coffee cup as the currents of steam and air rise.
During convection, mass is transferred from one location to another.
SUBTEST 2
Materials that do not conduct electricity well are called_____. -
ANSWERS-insulators
In a circuit, electrons travel along a conductor in _____ loops. -
ANSWERS-closed
The word circuit means _____ - ANSWERS-circle
Magnetism - ANSWERS-A magnet is any object that has the ability to
attract ferrous objects like iron, steel, nickel, and cobalt. Magnetite,
called lodestone for many years, is a naturally occurring iron ore that
has this ability. Most permanent magnets we use are manufactured
and are a combination or alloy of aluminum, nickel, cobalt, and iron,
although none of these metals is naturally magnetic. The magnetic
field in a permanent magnet is a result of electron spin. A magnetic
field is produced by spinning electrons in an atom. Every atom is
essentially a small magnet with a north pole and a south pole. In
nonmagnetic materials, electrons spin in random directions, so the
magnetic field is not noticeable. In magnets, however, the electrons all
spin in the same direction—they are aligned—and create a north pole
and a south pole. When a bar magnet is suspended at its center by a
string, it will rotate until one end points north. That end is called the
north pole of the magnet and the end that points south is called the
south pole. In magnets, unlike poles attract, and like poles repel.
Either pole, however, can attract iron objects such as pins and paper
,clips. That is because under the influence of a nearby magnet, each
pin or paper clip becomes a temporary magnet, with its poles arranged
in a way appropriate to magnetic attraction.
_____, called lodestone for many years, is a naturally occurring iron
ore that has this ability. - ANSWERS-Magnetite
Surrounding all magnets is a region called the _____ _____. -
ANSWERS-magnetic field
Electricity and magnetism are closely _____. The movement of
electrons creates a magnetic field, so electric current creates a
magnetic field. This magnetic property can be used to make powerful
electromagnets. You can make an electromagnet by simply coiling
wire around a thin rod made of iron or steel (a nail will work, too).
When an electric current moves through the wire, it makes a magnetic
field. The strength of the magnetic flow is dependent on the number
of times the wire is coiled around the rod, and the value of the current
is dependent on the flow through the conductor. The strength of the
electromagnet becomes greater as the number of loops of wire around
the core is increased. - ANSWERS-related
Chemical energy. - ANSWERS-Energy stored in bonds of atoms and
molecules is described as chemical energy. Gasoline and coal contain
stored chemical energy.
Electrical energy. - ANSWERS-Electrical energy is produced by the
movement of electrically-charged particles (electrons). The movement
of electrons through a conductor, such as a wire, is called current (or
, circuit) electricity. Lightning is an example of a giant spark of static
electricity, or the sudden movement of electrons from a cloud to
another surface.
Heat energy. - ANSWERS-Heat energy is created by the random
movement of molecules from a warm substance to a cool substance.
Temperature, measured in degrees, is an indication of the average
kinetic energy of the moving molecules—the speed at which they
move. If the molecules in a substance move slowly, the substance has
a low temperature. If the molecules move rapidly, the substance has a
high temperature. Heat energy is transferred in three ways.
Conduction. - ANSWERS-Conduction is the process by which energy
is transferred through matter by collisions between particles. It is the
transfer of heat energy from atom to atom within a substance. As one
molecule is heated, it begins to vibrate. As it does, it passes some of
its energy to other molecules around it. Through this process, all the
molecules of an object pass energy from one to another, until they are
all hot. This is conduction. For example, a metal spoon in a cup of hot
soup becomes warmer because the molecular motion of the hot soup
molecules is transferred, via collisions, along the length of the spoon,
to the molecules in the metal spoon.
Convection. - ANSWERS-Convection is the transfer of heat in a gas
or liquid by the circulation of currents from one region to another. In
convection, the molecules get heated and rise up; the cold molecules
sink and get reheated. Then they rise again to continue the cycle. For
example, heat leaves a coffee cup as the currents of steam and air rise.
During convection, mass is transferred from one location to another.
