physics test 3
Which is the smallest particle?
*quark neutron atom molecule proton
A nucleon has a mass of about
1 atomic mass unit. 1 amu. *both are the same. none of the above
What is the volume of a sugar cube that measures 1 cm on each side? What is the cross-sectional area of the cube? The total surface area?
1 cm3, 1 cm2, 6 cm2
Which contains more atoms?
1 kg of hydrogen
What is the mass density of water? What is the weight density of water?
1000 kg/m3; 9800 N/m3
What is the molecular mass of a water molecule?
18 amu
How many protons should be added to the nuclei of oxygen atoms so the resulting gas will glow red when an electric current is in it?
2
How many atoms are in this carbohydrate molecule, C6H12O6?
24
The atomic masses of two isotopes of cobalt are 59 and 60. What is the number of protons in each?
27,27
What is the number of orbiting electrons in each when the isotopes are electrically neutral?
27,27
How many individual atoms are in a water molecule?
3
What is the number of neutrons in each?
32,33
If a 1-kg object stretches a spring by 2 cm, then how much will the spring be stretched when it supports a 3-kg object? (Assume the spring does not reach its elastic limit.)
6 cm
How many shells are represented in the presently known periodic table?
7
If a gram of antimatter meets a kilogram of matter, the amount of mass to survive is
999 grams.
How does a molecule differ from an atom? Give an example.
A molecule is composed of two or more atoms bonded together: H2O.
What is meant by the term nucleon?
A proton or neutron
Distinguish between tension and compression.
A pulled-apart object is in tension; a pushed-together one is in compression.
What is meant by the elastic limit for a particular object?
A spring is elastic up to the limit and inelastic above it.
Who first explained Brownian motion and made a convincing case for the existence of atoms?
Albert Einstein
Why can't atoms be seen with a powerful optical microscope?
Atoms are much smaller than a wavelength of light.
What is a compound? Cite two examples.
Atoms of different elements with bonds between them: NaCl and H2O
What is a mixture? Cite two examples.
Atoms pressed together without bonding: air and salt and sand
What are the five most common elements in humans?
C, H, O, N, and Ca
What causes dust particles and tiny grains of soot to move with Brownian motion?
Collisions with invisible molecules
Since 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.
Which of these atoms has the largest number of neutrons in the nucleus?
Gold
What is the evidence that dark matter exists?
Gravitational forces within galaxies are too great to be accounted for with ordinary matter
What element has the lightest atoms?
Hydrogen
What is the most abundant element in the known universe?
Hydrogen
Which of the following is an element?
Hydrogen
Where in the atom is most of its mass concentrated? What is this mass composed of?
In the nucleus as protons and neutrons
How does one isotope differ from another?
It has a different number of neutrons.
How does the electric charge of a proton compare with the electric charge of an electron?
It is equal and opposite.
Who advanced the idea of atoms in the early 1800s?
John Dalton
Are most of the atoms around us younger or older than the Sun?
Most are older than the Sun
How are most of the elements with nuclei heavier than those of hydrogen and helium formed?
Nuclear fusion in stars
What is Hooke's law? Does it apply to elastic materials or to inelastic materials?
Stretch is proportional to force for elastic materials.
Iridium is not the heaviest atom found in nature. What, then, accounts for a chunk of pure iridium being the densest substance on Earth?
The iridium atoms are closer together in the crystalline form.
Why aren't heavier elements much larger than lighter elements?
The larger positive charge in the nucleus pulls the electrons into closer orbits.
What does the atomic number of an element tell you about the element?
The number of protons in its nucleus
How does the approximate number of atoms in the air in your lungs compare with the number of breaths of air in Earth's atmosphere?
The numbers are the about the same, 1023.
Why isn't cement needed between the stone blocks of an arch that has the shape of an inverted catenary?
The stones are held together by compressive forces.
Why can atoms be seen with an electron beam?
The wavelength of the electrons is smaller than an atom.
What occurs when a proton and an antiproton meet?
They annihilate each other.
Which is denser: an object that has a density of 1000 kg/m3 or one that has a density of 1 g/cm3?
They are the same density.
Why are the cross-sections of metal beams in the shape of the letter I instead of solid rectangles?
To reduce the weight of the beam while preserving the resistance to bending
Why do we say that a blob of putty is inelastic?
When deformed, it does not return to its original shape.
Why do we say that a spring is elastic?
When deformed, it returns to its original shape.
Which of the following is NOT a compound?
air
A force that determines the chemical properties of an atom is
an electrical force.
Nuclei of atoms that make up a newborn baby were manufactured in
ancient stars.
The periodic table of the elements is a list of __________.
atoms
A pair of helium nuclei fused together produces
beryllium.
Which of the following is NOT a mixture?
cake air beach sand granite *none of the above
If two protons and two neutrons are removed from the nucleus of an oxygen atom, what nucleus remains?
carbon
Two protons removed from an oxygen nucleus result in
carbon.
The name given to the shape of a sagging rope supported at its ends is a __________.
catenary
Heavy atoms are not appreciably larger in size than light atoms because the nuclei of heavy atoms have more
electric charge.
The volume of matter is due mostly to its
electrons
Which of the following are negatively charged?
electrons
The chemical properties of matter are due mostly to their
electrons.
To become a negative ion, does an atom lose or gain an electron?
gains
The element gold contains
gold atoms
An isotope is simply an atom that
has different numbers of neutrons for the same element.
A pair of hydrogen nuclei fused together produces
helium.
One neutron added to a helium nucleus results in
helium.
Which of these has the greatest number of protons in its nucleus?
lead
To become a positive ion, does an atom lose or gain an electron?
loses
Which of the following statements is true
molecules are the smallest subdivision of matter that still retain a substance's chemical properties
A granite block is mostly empty space because the atoms in the granite are
mostly empty space themselves.
The charge in the nucleus of an antimatter hydrogen atoms is __________.
negative
Which is the lightest particle?
neutron proton *electron all about the same
If a nitrogen atom and a slightly heavier oxygen atom have equal kinetic energies, which has the greater average speed?
nitrogen
If no molecules in a body could escape, would the body have any odor?
no
Mass number refers to the number of
nucleons in the nucleus.
Although solid matter is mostly empty space, we don't fall through the floor because
of electrical forces.
The number of protons in a neutral atom is balanced by an equal number of
orbital electrons.
Brownian motion is caused by
particles larger than atoms bumping into them.
Dark matter is considered to be __________.
plentiful in the universe
Atomic number refers to the number of
protons in the nucleus.
An element is distinct because of its number of
protons.
Heavier atoms are not proportionally larger than lighter atoms due to the greater number of protons
pulling surrounding electrons into tighter shells.
What element results if two protons and two neutrons are ejected from a radium nucleus?
radon
When carbon and oxygen atoms combine, energy is
released by the reaction.
Atoms can be photographed by
scanning electron microscopes. electron beams. *both of these neither of these
Assuming all the atoms exhaled by Julius Caesar in his last dying breath are still in the atmosphere, we breathe in at least one of them each
single breath
Which of these is most elastic?
steel
If we doubled the magnifying power of the most powerful optical microscope in the world, we would
still not be able to see or photograph an atom.
The difficulty of taking a photograph of an atom with light is
that atoms are smaller than wavelengths of light. unwanted diffraction. *both of these neither of these
Compared to the atoms that make up the body of an elderly person, the atoms that make up the body of a newborn baby are
the same age
Why aren't vertical columns needed to support the middle of domed stadiums, such as the Houston Astrodome?
the weight produces compression that supports the dome.
Which of the following statements is true?
there are only about 100 different kinds of atoms that combine to form all substances
Atoms heavier than helium were at one time manufactured by
thermonuclear fusion.
The number of atoms in a common water molecule is __________.
three
According to Hooke's law, if you double the force when stretching a spring, the elongation of the spring is normally __________.
twice as much
How many different kinds of elements are in a water molecule?
two
Which of the following elements has the most mass?
uranium
Which of these atoms has the greatest amount of electrical charge in its nucleus?
uranium
Which of these atoms has the greatest number of electrons?
uranium
