gvhg

Which set of coefficients balance the following chemical equation? ____ N2 + ____ H2 rightarrow ____ NH3

1, 3, 2

What is the total number of protons and neutrons in a water molecule?

18

How many different elements are in a water molecule?

2

How many shells are occupied by electrons in the gold atom (Au, atomic #79)?

6

Suppose that a certain atom possesses only four distinct energy levels. Assuming that all transitions between levels are possible, how many spectral lines will this atom exhibit?

6

When radium (A = 88) emits an alpha particle, the resulting nucleus has atomic number

86

Which of the following diagrams best represents the size of the atomic nucleus relative to the size of the atom: graphic(Fig 0327.bmp

A

The following three boxes represent the number of submicroscopic particles within a given volume of a particular substance at different temperatures. Which box represents the greatest density? Which box represents the greatest temperature?

A and C

How does an electron get from one lobe of a p orbital to the other?

The electron actually exists in both lobes at the same time.

Which is the smallest particle listed below?

a quark

The function of graphite in the first atomic reactor was to

absorb fast neutrons.

Fusing two iron nuclei yields a net

absorption of energy

Fissioning an iron nucleus yields a net

absorption of energy.

Both nitrogen and phosphorus are able to attract three more electrons to their outer shells because

all of the above.

A molecule has

all of these

The air in this room has

all of these

The half-life of a radioactive substance is independent of

all of these

In which lobe of a p orbital is an electron most likely found?

both lobes

In which of these processes is an element of matter changed into a completely different element?

both of these

If two protons are removed from an oxygen nucleus, the result is

carbon.

When a nucleus emits a beta particle, its atomic number

changes, but its mass number remains constant.

A chemical mixture is distinguished from a chemical compound in that

chemical compounds may be found in a chemical mixture.

Energy released by the Sun results from the process wherein atomic nuclei

combine

The operation of a cloud chamber relies on

condensation.

The number of elements in a period is

equal to the electron capacity of the shells.

An electron de-excites from the fourth quantum level to the third and then directly to the first. Two frequencies of light are emitted. How do their combined energies compare to the energy of the single frequency that would be emitted by de-excitation from the fourth level directly to the first level? Answer: The combined energies of the two frequencies emitted by the one electron is

equal to the energy of the single frequency.

Which experiences the least electrical force in an electric field?

gamma ray

Detonation of a fusion type hydrogen bomb is started by

igniting a small fission bomb.

When two light atoms fuse together, mass

is converted to kinetic energy of neutrons.

Compared to the sum of the masses of all the individual nucleons in their separate states that make up a nucleus, the mass of the composite nucleus is

less.

The circles in the boxes shown above represent the submicroscopic particles of a material in its three phases. From left to right these are

liquid, solid, and gas.

Solid matter is mostly empty space. The reason solids don't fall through one another is because

of electrical forces.

In bubble chambers, charged particles move in spirals because

of energy dissipation.

During a chemical reaction

old atoms stick around merely switching partners.

A TV screen looked at from a distance appears as a smooth continuous flow of images. Up close, however, we see this is an illusion. What really exists are a series of tiny dots (pixels). This is similar to a chemist's view of matter in that

on the submicroscopic level, chemist's find that matter is made of extremely small particles, such as atoms and molecules.

Artificially induced radioactive elements generally have

short half lives.

Which will leak more neutrons, two separate lumps of uranium or the same two lumps stuck together?

two separate lumps

How might the spectrum of an atom appear if its electrons were not restricted to particular energy levels?

A broad spectrum of all colors would be observed.

Germanium, Ge (number 32), computer chips operate faster than silicon, Si (number 14), computer chips. So how might a gallium, Ga (number 31), chip compare with a germanium chip?

A gallium chip would be even faster because the gallium is more metallic.

Why is it not possible for the STM to make images of the inside of an atom?

All of the above are reasonable answers.

How might you distinguish a sodium-vapor street lamp from a mercury-vapor street lamp?

Look at the street lamps through a spectroscope and match their spectral patterns to their respective atomic spectra

Some politicians take pride in maintaining a particular point of view. They think that a change of mind would be seen as a sign of weakness. How is a change of mind viewed differently in science?

Science deals with facts that are confirmed by experiments. A "change of mind" in science, therefore, is usually the result of new experimental evidence obtained from experiments.

Why are the atomic masses listed in the periodic table not whole numbers?

The atomic masses are average atomic masses.

Growth in a living body is best considered an example of a

Two of the above are correct.

Does an orbital or a shell of orbitals have to contain electrons in order to exist?

Two of the above are reasonable answers.

Which experiences the greatest electrical force in an electric field?

alpha particle

Nuclei of atoms that make up a newborn baby were made in

ancient stars.

When uranium-238 absorbs a neutron, it

becomes a beta emitter.

Of the three sciences—physics, chemistry, and biology—the most complex is

biology because it is based upon both the laws of chemistry and physics.

Although the nucleus of a carbon atom has a charge of +6, the charge experienced by carbon's valence electrons is different because

both A and B

Another interesting periodic trend is the density of the elements. We find that osmium, Os (atomic number 76) has the greatest density of all elements, and, with some exceptions, the closer an element is positioned to osmium, the greater its density. Based upon this trend, list the following elements in order of increasing density: copper, Cu, gold, Au, platinum, Pt, and silver, Ag.

copper, Cu < silver, Ag < gold, Au < platinum, Pt

The origin of cosmic rays is the

cosmos.

The most harmful radiations are those that

damage living cells.

The volume of matter comes mostly from its

electrons.

Evidence for the existence of neutrons did not come until many years after the discoveries of the electron and the proton. Give a possible explanation.

he neutron lacks an electrical charge.

Helium, He, is a nonmetallic gas and the second element in the periodic table. Rather than being placed adjacent to hydrogen, H, however, helium is placed on the far right of the table because

helium is most similar to other group 18 elements.

Strontium, Sr (number 38), is especially dangerous to humans because it tends to accumulate in calcium-dependent bone marrow tissues (calcium, Ca, number 20). This fact relates to the organization of the periodic table in that strontium and calcium are both

in group 2 of the periodic table.

As atoms get more massive they become smaller in size because

more mass means more protons, which act to pull electrons in closer to the nucleus.

The reason a granite block is mostly empty space is because the atoms in the granite are

mostly empty space themselves

The phase in which atoms and molecules no longer move is the

none of the above

In an electrically neutral atom, the number of protons in the nucleus is balanced by an equal number of

orbital electrons.

Each night you measure your height just before going to bed. When you arise each morning, you measure your height again and consistently find that you are 1 inch taller than you were the night before but only as tall as you were 24 hours ago! Is what happens to your body in this instance best described as a physical change or a chemical change? Be sure to try this activity if you haven't already.

physical change because it readily reverses

Detonation of a fission type atomic bomb is started by

pressing together several small pieces of uranium.

The weight of matter comes mostly from its

protons

Pure elements can be transformed into entirely different elements. This statement at the present time is

true

Does a 2-kg solid iron brick on Earth have twice as much mass as a 1-kg solid iron brick at the same place on Earth? Twice as much weight? Twice as much volume?

yes, maybe, and yes

How many electrons are unpaired in the outermost shell of sulfur (S, atomic number 16)

2

How many protons should be added to the nuclei of oxygen atoms so the resulting gas will glow red when an electric current flows through it?

2

Which set of coefficients balance the following chemical equation? ____ B2O3 + ______ C rightarrow ____ B4C3 + ____CO2

2, 6, 1, 3

The nucleus of an electrically neutral iron atom contains 26 protons. How many electrons does this iron atom have?

26

How many electrons are unpaired in the outermost shell of aluminum (Al, atomic number 13)?

3

Balance these equations: ____ H with subscript((2)) (g) + ____ N with subscript((2)) (g) rightarrow ____ NH with subscript((3)) (g)

3, 1, 2

How many electrons are in the outermost shell of strontium (Sr, atomic number 38)?

4

Which set of coefficients balance the following chemical equation? ____ Al + ____ O2 rightarrow ____ Al2O3 1) _______

4, 3, 2

How many electrons are in the outermost shell of phosphorus (P, atomic number 15)?

5

In both fission and fusion, mass

is changed to the form of kinetic energy.

To change mercury into gold, a pair of protons must be

neither of these

When a gamma ray is emitted by a nucleus, the nucleus then has appreciably less

neither of these

Which of the following are electrically neutral?

neutron

Light is emitted as an electron transitions from a higher energy orbital to a lower energy orbital. How long does it take for the actual transition to take place?

no time at all

Brownian motion has to do with the

random motions of atoms and molecules.

Assuming all the atoms exhaled by Julius Caesar in his last dying breath are still in the atmosphere, then we probably breathe one of those atoms with each

single breath.

An element emits 1 alpha particle, 1 positron, and 3 beta particles. Its atomic number

stays the same

The alkali metals (group 1) tend to form 1+ ions while the alkali-earth metals (group 2) tend to form 2+ ions because

the charges of these ions corresponds to the number of valence electrons that may be lost.

What makes an element distinct?

the number of protons

The purpose of coefficients in chemical equations is to make

the number of times each element appears as a reactant and as a product the same.

Suppose a hydrogen bomb were exploded in a box that could contain all the energy released by the explosion. Compared to the weight of the box before the explosion, the weight of the box after the explosion would be

the same

There are about as many atoms of air in our lungs at any moment as there are breaths of air in the atmosphere of

the whole world.

It's impossible for a hydrogen atom to emit an alpha particle

true

In a breeder reactor

uranium is converted into plutonium.

Some of the older known elements are the ones

whose atomic symbols and modern name don't match.

Why is the process of science not restricted to any one particular method?

The scientist needs to be open to all possibilities and different ways of doing science in order to gain as much knowledge as possible from his or her research.

If a pair of helium nuclei are fused together, the result is

beryllium.

When thorium (A = 90 ) emits a beta particle, the resulting nucleus has atomic number

none of these

If we doubled the magnifying power of the most powerful optical microscope in the world, we would

still not be able to see an atom.

About how many elements do you have access to as a consumer of market goods?

ten

The difference in the mass of a nucleon when outside an atomic nucleus compared to inside the nucleus depends on

the atomic number of the nucleus.

Humidity is a measure of the amount of water vapor in the atmosphere. Why is humidity always very low inside your kitchen freezer?

At the cold temperatures of your kitchen freezer, water molecules in the vapor phase are moving relatively slowly, which makes it easier for them to stick to inner surfaces within the freezer or to other water molecules.

The element bromine, Br (atomic number 35), has two major isotopes of similar abundance, both around 50%. The atomic mass of bromine is reported in the periodic table as 79.904 atomic mass units. Choose the most likely set of mass numbers for these two bromine isotopes

Br-79, Br-81