Physics Chapter 11
A nucleon has a mass of about
1 amu & 1 atomic mass unit.
Compared to the mass of a hydrogen atom, the mass of an oxygen atom is
16 times as great.
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
If a gram of antimatter meets a kilogram of matter, the amount of mass to survive is
999 grams.
What is meant by the term nucleon?
A proton or neutron
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
Which of the following are negatively charged?
Electrons
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
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
Distinguish between mass number and atomic mass.
Mass number is the number of nucleons; atomic mass is the total mass of an atom.
Are most of the atoms around us younger or older than the Sun?
Most are older than the Sun
Where did the heaviest elements originate?
Nuclear fusion in supernovae
If you place a Styrofoam cup on the table and a bunch of BBs move around it randomly, what will happen to the cup, and why?
The cup will move randomly in different directions because the BBs will exert unequal forces on the cup in different directions.
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 did the particles jiggle around?
The particles were struck by atoms, but unequally on different sides.
Compared with the energy it takes to separate oxygen and hydrogen from water, how much energy is released when they recombine?
The same amount of energy is released when they recombine.
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 of the following is NOT a compound?
air
A force that determines the chemical properties of an atom is
an electrical force.
A pair of helium nuclei fused together produces
beryllium.
The difficulty of taking a photograph of an atom with light is
both of these
What kind of attraction pulls electrons close to the atomic nucleus?
electric
Heavy atoms are not appreciably larger in size than light atoms because the nuclei of heavy atoms have more
electric charge.
Atoms can be photographed by
electron beams & scanning electron microscopes.
The chemical properties of matter are due mostly to their
electrons
The volume of matter is due mostly to its
electrons.
To become a negative ion, does an atom lose or gain an electron?
gains
An isotope is simply an atom that
has different numbers of neutrons for the same element.
An important feature of atoms is that they __________.
have wave properties
The electrical force is stronger between the nucleus and an inner electron for atoms of
high atomic number.
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 of the following are electrically neutral?
neutrons
If no molecules in a body could escape, would the body have any odor?
no
How are most of the elements with nuclei heavier than those of hydrogen and helium formed?
nuclear fusion in stars
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.
Dark matter is considered to be __________.
plentiful in the universe
An element is distinct because of its number of
protons
The mass of matter is due mostly to its
protons
Atomic number refers to the number of
protons in the nucleus.
Heavier atoms are not proportionally larger than lighter atoms due to the greater number of protons
pulling surrounding electrons into tighter shells.
Which is the smallest particle?
quark
What element results if two protons and two neutrons are ejected from a radium nucleus?
radon
What did Robert Brown see in his microscope?
random motions
When carbon and oxygen atoms combine, energy is
released by the reaction.
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.
What did Robert Brown see under the microscope?
specks of dust moving around
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.
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.
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
How many different kinds of elements are in a water molecule?
two
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
The chance that at least one of the atoms exhaled in your previous breath will be inhaled in your next breath is
very high