Physical science test 3

What is the approximate range of the nuclear strong force? (In other words, what is the distance over which the strong force is significant?)

About the size of a nucleus

In which of the following nuclear reactions is total charge conserved? alpha decay beta decay gamma decay electron capture All of the above

All of the above

A uranium atom splits into thorium and helium.

Alpha Decay

Carbon-14 ( 14C) is not stable and it spontaneously decays into nitrogen-14 ( 14N) and an electron by a radioactive beta-decay. Which of the following is true about the decay? A. Carbon-14 has more entropy than the products. B. The total charge of the carbon-14 is greater than the total charge of the products. C. One of the protons in carbon-14 changed into a neutron. D. The total number of nucleons stays the same. E. The mass of the nitrogen-14 plus the electron will be greater than the mass of the carbon-14 atom.

D. The total number of nucleons stays the same.

In which of the following processes is the end product more ordered than the reactants? (In which process does entropy decreases.) 2H2 (gas) + O2 (gas) = 2 H2O (gas) 2C8H18 (liquid) + 25O2 (gas) = 16CO2 (gas) + 18H2O(gas) C6H12O6 (solid) + 6O2 (gas) = 6CO2 (gas) + 6H2O (liquid) 2C7H5N3O6 (solid) = 3N2(gas) + 7CO(gas) + 5H2O(gas) + 7 C(solid) NaHCO3(solid) + C2H4O2(liquid)=C2H3NaO2(solid)+ H2O(liquid) + CO2 (gas)

2H2 (gas) + O2 (gas) = 2 H2O (gas)

Which of the following set of properties is most likely those associated with methane, a covalently bonded compound? A. solid at room temperature, opaque, good electrical conductor B. solid at room temperature, transparent, electrical conductor when dissolved in water C. gas at room temperature, colorless, does not conduct electricity when solid

C. gas at room temperature, colorless, does not conduct electricity when solid

The minimum amount of mass necessary for one fission to trigger another.

Critical mass

Which of the following correctly applies the law of increasing disorder to a refrigerator? A. Refrigerators violate the Law of Increasing Disorder because a heat flow from a cold region to a hot one represents a decrease of disorder. B. There is no violation of the Law of Increasing Disorder because a heat flow from a cold region to a hot region represents an increase of disorder. C. All the energy that leaves the cold region shows up in the hotter region, and therefore there is no change of disorder. D. It is true that the heat flow from the cold region to the hotter region increases order, but this is made up for by increasing the disorder of energy from another source. E. The Law of Increasing Disorder is not involved in this situation because the Law of Increasing Disorder does not apply to heat flow.

D. It is true that the heat flow from the cold region to the hotter region increases order, but this is made up for by increasing the disorder of energy from another source.

An increase in temperature means that disorder of a system increases, T or F

False

Compositions of alloys are general fixed in simple ratios T or F

False

Ionic bonds hold fatty acid molecules together in the solid state. true false

False

Molecular orbitals are the same shape as atomic orbitals. True False

False

a catalyst is a chemical that is present at the beginning of a reaction but not at the end True or False

False

Metals conduct better at higher temperatures, True or False

False, but they have better resistivity

A uranium atom splits into xenon and strontium plus a few neutrons.

Fission

In a bonding orbital between two atoms, where is the electron density the highest? (Where do you have the highest probability of detecting an electron?) In between the two atoms. The density is evenly distributed around both atoms. Around the outside of the two atoms.

In Between two atoms

A material that contains ions when dissolved or molten to produce an electrically conductive medium.

electrolyte

structural organization of salts and metals

extended or network substances

A very fast reaction has a very high activation energy, true or false

false

Fractures occur in crystals along lines or planes containing the strongest bonds. true false

false

It is possible to predict exactly when a radioactive nucleus will decay. true false

false

Molecular substances melt at very high temperatures. true false

false

The forces between the N2 molecules in a container of N2 are very strong. true false

false

colder = less ordered True or false

false

If a certain LED (doped semi-conductor) is cooled in liquid nitrogen, the color moves to a higher frequency. What happens to the band gap? It increases in energy. It decreases in energy. It doesn't change.

increases in energy

Forces between molecules

intermolecular forces

A charged atom or molecule with unequal numbers of protons and electrons formed by losing or gaining electrons.

ion

The chemical bond that binds metallic ions to nonmetallic ions by electrical attraction.

ionic bonding

Which of the following is NOT important in the determining the characteristics of fatty acids? covalent bonds dispersion forces hydrogen bonds ionic bonds

ionic bonds

geometry around a carbon atom with a triple bond

linear

in the upper atmosphere (also known as the ozone hole). As a catalyst, Cl may be lowering the activation energy of some reaction involving ozone. be consumed in the reaction. cause bonds to become weakened. a and c. a, b, and c.

lowers the activation energy of some reaction involving ozone.

The ability of atoms to change relative position without weakening the bonds between them.

malleability

Positive nuclei moving about in a sea of electrons is referred to as

metallic bonding

structural organization of water

molecular substances

Which of the following is a reversible process? A man diving into a pool. Water falling down Niagara Falls. A pendulum swinging. Scrambling eggs. None of the above.

none of the above

Silicate material in which all silicate tetrahedra are bonded with equal strength to four other tetrahedra

quartz

A measure for how difficult it is to make a current move through a substance

resistively

A substance formed from the ionic bond of a metal with a nonmetal.

salt

Contains only C-C single bonds

saturated fatty acids

substances that conduct electricity better than insulators but not as good as conductors

semiconductors

geometry around a carbon atom with four single bonds

tetrahedron

Building block of most rocks

Silicate

A state of matter in which atoms or ions are arranged in an orderly, repeating pattern

crystal

An electron which is not focused around any one nucleus

delocalized electron

What happens to the valence electrons as an ionic compound is formed?

The metal atom's valence electrons are given to the non-metal

Who makes alloys easiest of all compositions?

The metals under Carbon

Which of the following pairs of metal is most likely to form alloys of all compositions? Ba and Ga Sn and Pb Li and Bi

Sn and Pb

A balloon filled with helium at room temperature at sea level or the same balloon at an altitude of 8000 feet where the air is colder. Which is more ordered? balloon at 8000 feet balloon at sea level

Balloon at 8000 feet

Uranium-238 alpha decays, emitting a helium-4 nucleus. What is the mass number of the product?

234

Which of the following nuclear reactions has a proton changed into a neutron? 14C --> 14N + -1e 238U --> 234Th + 4He 40K + -1e --> 40Ar 235U + 1n --> 92Kr + 141Ba + 31n

40K + -1e --> 40Ar

Which of the following is a legitimate radioactive decay because both charge and mass number are conserved? 79,198Au --> 80 198Hg + +10 positron + 0 0 neutrino 27,60 Co --> 26 60 Fe + -1 0 electron + 0 0 neutrino 84,212 Po --> 82 208 Pb + 2 4 He 80,198 Hg + -1 0 electron --> 80198 Hg + 0 0 gamma ray 611 C --> 5 11 B + +1 1 proton + 0 0 neutrino

84,212 Po --> 82 208 Pb + 2 4 He

Carbon-14 is a radioactive isotope of carbon. Nitrogen-14 is naturally occurring. If you compare the two, what would you expect to find? A C-14 nucleus has more mass. An N-14 nucleus has more mass. The masses of the two are equal.

A C-14 nucleus has more mass.

A metal can best be described as which of the following? A network solid consisting of individual negatively charged atoms A network solid consisting of positively-charged and negatively-charged ions A molecular solid consisting of charged atoms An ionic solid consisting of covalently-bonded atoms A network solid consisting of positively charged atoms in a sea of electrons

A network solid consisting of positively charged atoms in a sea of electrons

Which of the following processes is closest to an ideal reversible process? Two cars colliding. Using a toaster to make toast. A pendulum swinging. A ripe peach rotting. An ice cube floating in a glass of water at zero degrees.

An ice cube floating in a glass of water at zero degrees.

A triglyceride is made by combining Glycerol and carbonate An organic acid and glycerol Glycerol and mica Asbestos and quartz

An organic acid and glycerol

Silicate material with a stringy structure

Asbestos

The atomic orbitals for potassium (K) and bromine (Br) are similar to those for sodium and chlorine. However they differ in that the potassium and bromine atomic orbitals are higher in energy than their counterparts. Why is this? A. K and Br valence electrons are closer on average to their nucleus than Na and Cl valence electrons. B. K and Br valence electrons experience a stronger attraction to their nucleus because of a larger atomic volume and smaller nuclear charge. C. K and Br valence electrons experience a stronger attraction to their nucleus because of smaller atomic volume and increases nuclear charge. D. K and Br valence electrons experience a weaker attraction for their nucleus because there are fewer positively charged protons. E. K and Br valence electrons experience a weaker attraction for their nucleus because they are farther from the nucleus.

E. K and Br valence electrons experience a weaker attraction for their nucleus because they are farther from the nucleus.

In order for a chemical reaction to occur: Energy must decrease as a result of the reaction. Entropy must increase as a result of the reaction. Energy and entropy must both increase. Energy and entropy must both decrease. Energy must decrease and entropy must increase.

Entropy must increase as a result of the reaction

How to remember energy sources in order of most ordered to disordered

Gosh Mary Kay Needs Extra Clearance Today

Energy Sources in order of most ordered to disordered

Gravitational Potential and Macroscopic Kinetic Nuclear Potential Energy Electrical Household Chemical Potential Thermal Energy (heat or microscopic kinetic)

Why is a high temperature required for nuclear fusion to occur?

High temperatures are required to allow the nuclei to have enough kinetic energy to overcome the electromagnetic repulsion and get close enough for the strong force.

Which of the following is a true statement about melting and boiling points in materials made of covalent molecules? Molecules that contain double bonds melt and boil at higher temperatures because the bonds are stronger. Molecules that contain triple bonds are the most likely to be gases at room temperature. Molecules that are polar have lower melting and boiling points than non-polar molecules. Hydrogen bonding between molecules increases melting and boiling points. Van der Waals (dispersion) forces lower melting and boiling points.

Hydrogen bonding between molecules increases melting and boiling points.

What happens when Ca(NO3)2 dissolves in water?

It will break apart but not completely as it mixes in the water

What best describes how the carbon dioxide molecules would behave if mixed with water?

It would dissolve poorly or not at all because they are not polar

The Carbon structures

Methane Ethane Propane Butane

silicate material with layer like structure

Mica

Ions composed of more than one covalently-bound atom.

Molecular Ions

How to remember the carbon structures

Mother Eve Prays Butt Naked

Which of the following tends to have the highest melting and boiling points? Atomic matter molecular matter network matter

Network matter

Property of absorbing photons throughout the electromagnetic spectrum.

Opacity

Which of the following pairs of metals is most likely to form alloys of all proportions? Cs and In Pb and K Pt and Au

Pt and Au

How easily light bounces off the surface of a substance.

Reflectivity

Best geometric arrangement of four bonds around a central atom

Tetrahedron

What do you need to know about vibrational spectroscopy (the lines that show relationship to infrared)

That if elements show similar lines, they are in the same family

Charge is always conserved in an nuclear process. true false

True

In asbestos drawings, black lines mark where it is weak and wants to pull apart, True or False

True

Light can only be seen through metal that is so thin it is only a few atoms thick. T or F

True

Mass changes in nuclear processes. true false

True

The electromagnetic force acts as a disruptive force in large nuclei, creating repulsions which help in fission. T or F

True

The electromagnetic force extends over a longer distance than the strong nuclear force. true false

True

The melting point of saturated fatty acids increases with increasing number of carbon atoms. true false

True

Fusion makes energy because

You're fusing together small atoms with large average nucleon mass into larger atoms with smaller nucleon mass, so the excess mass gives off a lot of energy

Fission makes energy because

You're splitting large atoms with larger average nucleon mass into smaller atoms with smaller nucleon mass, so the excess mass gives off energy

metal-metal compounds

alloy

The endings that say what types of bonds there are

ane: only single bonds ene: 1 double bond yne: 1 triple bond

The structural organization of group 8A elements

atomic matter

A characteristic of ionic substances, such as salts, that readily shatter when struck a sharp blow.

brittleness

A set of molecular orbitals so tightly spaced that the energies overlap each other.

conduction band

chemical bond between two non-metals characterized by sharing of valence electrons

covalent bond

the degree to which a substance conducts heat

thermal conductivity

What happens to semiconductors when you heat them up?

they act more like metals

What happens to the valence electrons when an ionic compound is formed? They typically end up with more energy. They typically end up with less energy. They end up with exactly the same energy.

they typically end up with less energy

The purpose of the control rods in a nuclear fission reactor is

to absorb neutrons, thus limiting the number of nuclei undergoing fission.

Which has the highest melting point? Saturated fats unsaturated fats transfats

trans fats

who makes alloys easiest of all proportions?

transition metals

Salts readily transmit light, so they are said to have this property:

transparency

Semiconductors conduct better at higher temperatures, true or false

true

The strong force between two protons is stronger than the electric repulsion between two protons. true false

true

Formula for entropy

universe = system + surroundings

Contain C=C double bonds

unsaturated fatty acids