SCMH: Exam #3

On average, each person in the United States uses energy at the rate of about 1 kilowatt-hour/each hour 10 kilowatt-hours/each hour 100 kilowatt-hours/each hour 1,000 kilowatt-hours/each hour

1 kilowatt-hour/each hour

Starting with 6 grams of a substance that is known to be radioactive, if we measure the mass remaining after 1,000 days and find 3 grams is remaining, what is the half-life? 6,000 days 3,000 days 500 days 1,000 days

1,000 days

A particular isotope has a half-life of 10 minutes. If we start with 2,000 atoms now, in a half hour we will have how many atoms converted into something different? 250 atoms 1,750 atoms 2,000 atoms 125 atoms 500 atoms

1,750 atoms

If an unstable nucleus has a half-life of 2 days and we start with 256 g of this material, how many grams will be left after 8 days? 64 g 8 g 32 g 16 g

16 g

In the innermost electron shell, there can only be _____ electrons.

2

Methane combusts in the presence of oxygen to produce carbon dioxide and water, as shown by this reaction: CH4 + O2 --> CO2 + H2O 2 : 1 1 : 1 2 : 2 1 : 2

2 : 1

In the periodic table, carbon is element #6. This means it has six electrons. How many valence electrons does carbon have?

4

In the periodic table, neon is element #10. How many electrons does neon have in its outermost electron shell?

8

How is the organization of the Periodic Table of Elements related to the number of electrons in the outermost shell of atoms? The electrons within elements in the leftmost column fill the lowest energy shells. A different column in the Periodic Table corresponds to a different shell. A different row in the Periodic Table corresponds to a different shell. Within a given row, all electrons are within the same shell.

A different row in the Periodic Table corresponds to a different shell.

How is the organization of the Periodic Table of Elements related to the number of electrons in the outermost shell of atoms? Within a given row, all electrons are within the same shell. The electrons within elements in the leftmost column fill the lowest energy shells. A different column in the Periodic Table corresponds to a different shel A different row in the Periodic Table corresponds to a different shell.

A different row in the Periodic Table corresponds to a different shell.

Which of the following best describes an alloy? A mixture of bonded atoms of only one metallic element A mixture of covalently bonded atoms of at least two elements A mixture of metallically bonded atoms of at least two elements A mixture of ionically bonded atoms of at least two elements

A mixture of metallically bonded atoms of at least two elements

What is a polar molecule? A molecule with one side electrically positive and the other side electrically negative A molecule with one side being a magnetic North Pole and the other side a magnetic south pole A molecule that is formed in the -2 K temperature of interplanetary space A molecule with one side possessing much more atomic mass than other side

A molecule with one side electrically positive and the other side electrically negative

If we take a carbon nucleus and add a proton to the nucleus, what do we get? A carbon nucleus A boron nucleus An oxygen nucleus A nitrogen nucleus

A nitrogen nucleus

What is the ITER project? A new process to dispose of nuclear waste A project to produce electricity using fusion A group trying to stop the building of nuclear power plants An attempt to produce electricity using fission A project to produce electricity from clean coal

A project to produce electricity using fusion

Often combine with oxygen to form colorless materials with high melting temperatures

Alkali Earth metals

soft, silvery elements that form salts by combining 1 : 1 with halogens (Column 17)

Alkali metals

An ionic bond forms where the following happens? Atoms that like to share electrons interact with each other. Atoms that do not like to share electrons interact with each other. An atom that likes to give up an electron interacts with an atom that likes to take electrons. An atom that likes to share electrons interacts with an electron that likes to take electrons.

An atom that likes to give up an electron interacts with an atom that likes to take electrons

Radioactivity was first discovered by Marie Curie Antoine Becquerel Pierre Curie Albert Einstein

Antoine Becquerel

_____ is an example of an exothermic reaction. Dissolving salt Creating electricity Burning wood Making ice None of the above

Burning wood

Which of the following chemical reactions shows combustion? CH4 + 2O2 --> CO2 + 2H2O HCl + NaOH --> NaCl + H2O Fe+2 + H2O --> FeO + H2 (g) Pb + PbO2 --> 2H2SO4 + 2H2O CaO + 2HCl --> CaCl2 + H2O

CH4 + 2O2 --> CO2 + 2H2O

An atom has a nucleus containing 20 protons and 22 neutrons. What is the isotope and what is its atomic mass? Calcium-20; 20 Calcium-42; 42 Titanium-22; 22 Titanium-42; 42

Calcium-42; 42

The first to prove an atom is mostly empty space by using alpha particles was: Thomson Dalton Democritus Rutherford Mendeleev

Dalton

When the energy available within the nucleus is released, it follows Newton's law of gravity Einstein's law relating energy to mass and the speed of light Rutherford's rule of radioactive decay Faraday's rule of electromagnetism

Einstein's law relating energy to mass and the speed of light

In Rutherford's gold foil experiment, how did he know that his alpha particles that scattered at large angles did not simply interact with an electron? Electrons have much less charge than alpha particles Electrons are much less massive than alpha particles Electrons are much smaller in size than alpha particles Electrons are much slower than alpha particles

Electrons are much less massive than alpha particles

Of those elements listed below, which is the most reactive atom? Element 3, lithium Element 2, helium Element 26, iron Element 92, uranium

Element 3, lithium

The difference between nuclear fusion and nuclear fission is that: Energy is released from fusion, but not from fission Fusion splits apart a nucleus; fission combines two nuclei into one Fusion combines two nuclei into one and fission splits the nucleus apart Energy is released from fission, but not from fusion Required for atomic bomb explosions

Fusion combines two nuclei into one and fission splits the nucleus apart

Why will a grain of pollen placed in water move about erratically? In a sufficiently short period of time, the number of water molecules bumping into it from all sides is not the same. Currents within the water keep the pollen grain moving about. The water molecules in the water are not uniformly distributed and the grain of pollen moves from one region of lower density to another The pollen grain moves from one region of least impurity to another

In a sufficiently short period of time, the number of water molecules bumping into it from all sides is not the same

Which of the following is an accurate statement about the neutron? The mass of the neutron depends on the situation due to the variable amount of energy that is created from lost mass. Its mass is less than the mass of the proton plus electron Its mass is greater than the mass of the proton plus electron Its mass is equal to the mass of the proton plus electron

Its mass is greater than the mass of the proton plus electron

Recognized some material can't be broken down further. Could be atoms or molecules. Atomism: for every chemical element there's corresponding atoms Molecule: any cluster of atoms. Can be aw few as two or up to thousands

John Dalton

Lithium typically loses one electron and oxygen typically gain two electrons. What ionic molecule forms between lithium and oxygen? LiO2 LiO4 Li2O LiO

Li2O

The arrangement of elements into a periodic table was originally proposed by Bohr Democritus Dalton Mendeleev

Mendeleev

created the periodic table

Mendeleev

Very low reactivity, colorless, odorless

Noble or Inert gas

_____ reacting with iron is an example of oxidation. Oxygen Carbon Sodium Chlorine None of the above

Oxygen

How many elements make up most (~99%) of the Earth's mass? Several dozen. All elements are present in roughly equal amounts. Six. Two or three.

Six

The half-life is described by which of the following? The amount of time that elapses before half of the original sample of a radioactive material has decayed The amount of time that elapses before one half of one half of the original sample of a radioactive material has decayed Half the average lifespan of an unstable nucleus Half the lifespan of the longest-lived unstable nucleus

The amount of time that elapses before half of the original sample of a radioactive material has decayed.

What was the first constituent of an atom to be discovered? The ion The proton The neutron The electron

The electron

The Sun's power comes from which of the following? The fusion of four hydrogen-1 nuclei into 2 hydrogen-2 nuclei The fusion of four helium-4 nuclei into an oxygen-16 nucleus The fusion of two hydrogen-1 nuclei into a helium-4 nucleus The fusion of four hydrogen-1 nuclei into a helium-4 nucleus

The fusion of four hydrogen-1 nuclei into a helium-4 nucleus

Which of the following are accurate statements about the nucleus of an atom? The interactions within the nucleus of some atoms occasionally send matter and energy out of the atom The nucleus contains very little of an atom's total energy The interaction within the nucleus alone control chemical behavior of the atom The nucleus contains the greatest part of an atom's total volume

The interactions within the nucleus of some atoms occasionally send matter and energy out of the atom.

The atomic number of an element best corresponds to which of the following? The number of neutrons in the nucleus of an atom of that element. The number of protons in the nucleus of an atom of that element. The mass of an atom of that element. The number of electrons orbiting the nucleus of an atom of that element.

The number of protons in the nucleus of an atom of that element.

How do two isotopes of the same element differ? They have a different atomic number Their neutrons differ in number Their nuclei have different number of protons Their electrons have different orbits They have different electrical charges

Their neutrons differ in number

What was one of the original motivations for grouping the elements in columns? They are grouped according to similar sizes They are grouped according to similar chemical behavior They are grouped according to similar masses They are grouped according to the order in which they were discovered

They are grouped according to similar chemical behavior

What type of bond is formed when two hydrogen atoms share a pair of electrons to form a hydrogen molecule? a covalent bond an ionic bond a metallic bond a hydrogen bond

a covalent bond

If one were to conduct a cutting experiment like that described by Democritus wherein he envisioned cutting paper into smaller and smaller pieces using the world's sharpest knife, what would the smallest identifiable bit of paper be? an atom a molecule a tiny part of an atom an element like hydrogen

a molecule

To see an everyday example of oxidation, you might observe: glass breaking growing hair a nail rusting a light bulb shining a thunderstorm

a nail rusting

The tiny particle released during beta decay that has no electric charge is an electron a neutrino a proton a neutron

a neutrino

An electrically neutral particle in the nucleus of an atom is called: a nucleus an ion a proton a neutron an electron

a neutron

If you take an electrically neutral atom of sodium (11) and remove one electron, you wind up with which of the following? a positively charged ion of sodium a negatively charged ion of sodium a positively charged atom of neon (10) a negatively charged atom of neon (10)

a positively charged ion of sodium

Metals are held together because of: a sea of electrons a transfer of negative electrons an attraction between the polar molecules a sharing of electrons the lack of attraction between the inert atoms

a sea of electrons

Covalent solids are held together because of: a sharing of electrons a transfer of negative electrons the lack of attraction between the inert atoms a sea of electrons an attraction between the polar molecules

a sharing of electrons

Ionic solids are held together because of: the lack of attraction between the inert atoms a sharing of electrons a transfer of negative electrons a sea of electrons an attraction between the polar molecules

a transfer of negative electrons

Metallic bonds create materials with properties that make them: good insulators brittle able to change shape without breaking polar as hard as diamonds

able to change shape without breaking

The pH of a particular water-based solution is 3.9, therefore the solution is: carbonated basic neutral acidic

acidic

If a chlorine atom receives an electron from a sodium atom, the resulting chloride ion remains electrically neutral acquires one unit of negative charge acquires one unit of positive charge acquires two units of positive charge

acquires one unit of negative charge

If a sodium atom loses an electron to a chlorine atom, the resulting sodium ion remains electrically neutral acquires one unit of negative charge acquires one unit of positive charge acquires two units of positive charge

acquires one unit of positive charge

If an atom emits two protons and two neutrons, the atom has: emitted an alpha particle produced a small amount of helium changed the mass and chemical identity of the atom created a daughter nucleus from the parent nucleus all of these are correct

all of these are correct

The type of radioactive decay that causes the release of two protons and two neutrons is alpha decay beta decay gamma decay none of the above

alpha decay

Polar molecules are: always dipoles sometimes dipoles never dipoles monopoles none of the above

always dipoles

Any material that releases positive hydrogen ions when dissolved in water is a base an acid a polymer a crystal

an acid

An example of a metallic bond is: organic compounds hydrogen gas DNA an alloy NaCl

an alloy

An atom that has gained or lost electrons is known as: an ion a proton a nucleus an electron a neutron

an ion

One atom permanently receives an electron from another atom during the formation of a covalent bond an ionic bond a metallic bond a hydrogen bond

an ionic bond

Photons are emitted when electrons: are in an excited state jumps to a ground state. collide within the electron cloud. are in the ground state and jumps to an excited state. none of the above. stay in allowed orbits.

are in an excited state jumps to a ground state.

The _____ of an element is the same as the number of protons within the nucleus of that element. atomic number atomic mass valence number all of the above none of the above

atomic number

Mendeleev based the original periodic table on the: atomic weights. number of neutrons in the nucleus of the atom. number of protons in the nucleus of the atom. valence electrons. average atomic masses.

atomic weights

John Dalton proposed the hypothesis of laser beams quantum leaps the Periodic Table of the Elements atomism

atomism

According to Democritus, all material was formed of molecules atoms fire and earth air and water

atoms

The strongest type of bond is covalent van der Waals metallic ionic inert

covalent

Noble gases are called so because they: are very valuable are considered more important than other elements can exist in more forms than other elements can chemically interact with many other elements don't chemically interact with other elements

don't chemically interact with other elements

Splitting by electricity

electrolysis

The negatively charged particle that is a part of an atom is the photon neutron proton electron

electron

Oxidation is the process in which: electrons are transferred from one atom to another two substances react to form water and a salt oxygen is formed spontaneously from higher number elements solids precipitate down to the bottom of the solution

electrons are transferred from one atom to another

Helium, gold, carbon, aluminum, and copper are examples of elements atoms molecules quantum groups

elements

Exothermic and endothermic chemical reactions differ in that: only exothermic reactions can be observed in everyday energy is given off only in exothermic reactions energy is given off in endothermic reactions the total energy in all involved electrons is the same before and after an exothermic reaction the total energy in all involved electrons is the same before and after an endothermic reaction

energy is given off only in exothermic reactions

Solids that do not have long-range order to the arrangement of their atoms called: crystalline solids ionic solids metallic solids glass van der Waals solids

glass

Inert gases have very little in common form a compound known as a salt have similar chemical properties all contain oxygen are also called halogens

have similar chemical properties

An atom with two protons in the nucleus is called:

helium

During Rutherford's experiment documenting alpha decay, alpha particles led to the production of hydrogen gas neutrinos gamma rays helium atoms

helium atoms

A high octane rating in gasoline causes less engine 'knock' because: high octane gas is easier to distill than low octane the isomer n-heptane is the primary component high octane can withstand high compression in a cylinder without igniting high octane contains small amounts of isooctane high octane is less complex hydrocarbons than low octane

high octane can withstand high compression in a cylinder without igniting

In the periodic table of the elements, the only element lighter than helium is: silicon hydrogen oxygen argon neon

hydrogen

If you use an electrical current to break down water, you get what two gases? hydrogen and carbon carbon and oxygen hydrogen and oxygen carbon and dioxide

hydrogen and oxygen

Which six elements are most common in living organisms?

hydrogen, carbon, oxygen, nitrogen, phosphorus, and sulfur

Sodium chloride (NaCl) atoms from a crystal lattice that is held together by: salt bonds hydrogen bonds van der Waals bonds ionic bonds covalent bonds

ionic bonds

Table salt forms a crystal in which the elements are held together by covalent bonds ionic bonds metallic bonds hydrogen bonds

ionic bonds

An element with an atomic number of 8: has eight electrons in the outer shell of each atom contains atoms with four protons and four neutrons is composed of atoms with only eight protons as six protons and two neutrons was the eighth element discovered

is composed of atoms with only eight protons

The arrangement of the atoms in glass is: regular and repeating irregular in all places locally regular but overall not regular all of the above none of the above

locally regular but overall not regular

Which of the following is not characteristic of hydrogen bonds? polar molecules linking the two sides of the DNA double helix separation of positively and negatively charged ions malleability and metallic bonds links of hydrogen to oxygen and other negative ions

malleability and metallic bonds

Because of the distribution of electrical charges in metals, metals tend to be: dull (not shiny) undesirable for industrial purposes electrically non-conductive malleable

malleable

Electrons and protons differ in their: charge only energy mass and charge mass only shape

mass and charge

Atoms are mostly comprised of: mass squared times velocity. mass times the speed of light. mass divided by the speed of light, then squared. mass times the speed of light squared none of the above

mass divided by the speed of light, then squared

Which makes the best electrical conductor? hydrogen bonds covalent bonds metallic bonds ionic bonds polymers

metallic bonds

Two or more atoms stuck together are a(n) element molecule double atom nucleus

molecule

The dense, central portion of an atom is its quantum group electron photons nucleus

nucleus

The elements in the periodic table are arranged based on the: number of protons in the nucleus valence electrons at all times number of electrons surrounding the nucleus number of neutrons in the nucleus mass of the nucleus

number of protons in the nucleus

Atoms in the same column of the periodic table have the same: outer shell electron configurations inner shell electron configurations atomic mass and atomic size number of electrons in the nucleus number of neutrons in the nucleus

outer shell electron configurations

During some chemical reactions, one atom transfers an electron when combining with another atom. The atom that loses the electron is said to be oxidized reduced decreased polymerized

oxidized

Which six elements make up 99% of Earth's surface

oxygen, silicon, magnesium, iron, aluminum, calcium

The science of spectroscopy examines the nature of _____ emitted from excited atoms. electrons protons photons neutrons

photons

An example of something that is not a polymer is: spider webs and plastic plasma and gas nylon and cotton fur and cellulose meat

plasma and gas

The positively charged particle found in the nucleus of the atom is the proton neutron electron photon

proton

In atomic science, the Z number refers to the number of _____ in the nucleus of an atom. subatomic particles electrons protons neutrons none of the above

protons

helium, carbon, aluminum, copper, gold

pure elements

The Nobel laureate Marie Curie died as a result of: child birth an auto accident natural causes radiation exposure homicide

radiation exposure

Chemical bonds occur when electrons are _____ atoms. stripped off expelled from rearranged between all of the above none of the above

rearranged between

The total collection of photons emitted by a given atom is called its energy signature spectrum periodic position electromagnetic image

spectrum

Which force holds the nucleus together? electromagnetic force centripetal force gravity strong force weak force

strong force

Compounds of what element may be released into the atmosphere upon burning of fossil fuels and lead to formation of acid rain? carbon sulfur lead mercury

sulfur

In the periodic table of the elements, a period refers to the: horizontal row vertical column number of neutrons atomic mass of the atom number of protons in the atom

the horizontal row

A scientist who uses carbon-14 dating is actually measuring the: age of the igneous rocks. time that an artifact was made. number of carbon ions in a material. time of death of a living thing. age of the Earth.

time of death of a living thing.

Radioactive tracers are used to date geological and anthropological items to produce electrical energy in a fission reactore to produce electrical energy in a fusion reactor to help diagnose diseases

to help diagnose diseases

During the nuclear fission reaction in a reactor that generates electricity two alpha particles unite to form a molecule of helium uranium-238 releases beta particles uranium-235 releases neutrons uranium-234 atoms fuse, with the release of large amounts of energy

uranium-235 releases neutrons

The electrons at the outer energy level of the atom are called: outer field electrons valence electrons van der Waals electrons ionic electrons the atomic number

valence electrons

The weakest type of bond is: metallic covalent ionic inert van der Waals

van der Waals

Which of the following common household products is an acid? milk ammonia detergent vinegar salt

vinegar