Exam 3 Flashcards
the density of a 2-cubic meter block of mass of 600 kg is
300 kg/m3
airplane flight best illustrates
Bernoulli’s principle
in the early 1800 Robert Brown made an observation that advanced the atomic hypothesis. What was the observation?
jiggling of dust particles which was interpreted as particles being struck unequally in different sides by unseen molecules
an element is distinct because of its number of
protons
If sodium atom loses an electron from its electron cloud, the resulting atom is
a sodium ion
a spring is stretched 10 cm by a suspended 1-kg block. If two springs side-by-side are sued to suspend the 3-kg block, each spring will then stretch
15 cm
one neutron added to helium nucleus results in
beryllium
where do naturally occurring elements heavier than boron come from?
they are made by stars in nuclear fusion and supernova events
how does one isotope differ from another?
it has a different number of neutrons
which of these atoms has the largest number of protons in the nucleus?
neon
consider a mouse and an elephant. which is stronger, and which is stronger scaled proportionally for its weight?
an elephant is stronger, but a mouse is stronger scaled proportionally for its weight
the air of the atmosphere is best described as
a mixture
how does the arrangement of atoms in a crystalline substance differ from the arrangement in a noncrystalline substance?
atoms in crystals are in ordered array with long range order. In amorphous materials, they have only short range order
which of these particles has the least mass?
electron
are most of the atoms around us here on earth younger or older than the sun?
most are older than the sun
the volume of an atom is due mostly to its
electron clouds
an important feature of the electrons that are in the electron shells about the nucleus of an atom is
that these electrons have wave properties
an object is fully submerged in water. the buoyant force on the object is equal to
the weight of the water that the submerged object displaces
the water is poured out of a 1-liter jug, the lid replaced and the empty jug submerged in water. which of the following is true about the buoyant force? Remember 1 liter of water has a mass of 1 kilogram
the buoyant force is about 10 N
compared to a bar of pure gold, the density of a pure gold ring is
the same
when subjected to a deforming force, we find that play dough is far more elastic than an aluminum rod would be
false
when a boat sails from fresh water to salt water, the boat will float
higher in the water
since the atoms are mostly empty space, why don’t we fall through a floor we stand on?
electrons in one atom repel the electrons in another
that volume occupied by a gas is reduced by half while the temperature remains constant. we will now find that
the pressure is double
buoyant force acts upward on a submerged object because
pressure from the liquid against the bottom of the object is greater than pressure against its top
a pair of hydrogen nuclei fused together produces
helium
what does the atomic number of an element tell you about the element?
the number of protons in its nucleus
which of the following is NOT true in regard to the surface tension of water
is responsible for buoyancy
why cant atoms be seen with a powerful optical microscope?
atoms are much smaller than a wavelength of light
which of the following is TRUE about drinking water from a straw
air pressure pushes water up the straw so straws can only be most 10.3 in height
consider several roped all made of the same type of fibers. in general the strongest rope will be the one
with the greatest cross sectional area
the discovery of the Higgs boson will likely
change our idea of what it means for matter to have mass
the cosmos is comprised mostly of
dark energy and dark matter
it would be easier to pull the evacuated Magdeburg hemispheres apart if they were
20 km above the ocean
If you had a penny for every atom in a penny, how much money would you have?
enough to give every person on the planet 40 billion dollars
when the curve of an arch matches the inverted image of drooping chain held at both ends, the curve is called a
catenary
which of the following is true about nucleons?
they are made of quarks
the volume of water displaced by a floating 20-ton boat
is the volume of 20 tons of water
which of the following is NOT true?
the buoyant force on a fully submerged object depends upon the depth. the deeper the object the greater the buoyant force
as a balloon rises higher and higher into the atmosphere its
volume increases
