Science final

If an atom of an element has a mass number of 32 and 20 neutrons in its nucleus, what is the atomic number of the element?

12

If an atom of tin has a mass number of 118 and an atomic number of 50, how many neutrons are in its nucleus?

68

If an atom has 34 protons and 40 neutrons, what is its mass number?

74

How many elements occur naturally?

92

Which phrase best describes a metallic bond? a. A bond formed by a metal b. the attraction between a metal anion and a shared pool of electrons d. the attraction between a metal cation and a shared с. a bond that forms between a metal and a nonmetal pool of electrons

A. A bond formed by a metal

In general, a __________metal will be more reactive than an alkaline earth metal in the same period.

Alkali

In Rutherford's gold foil experiment, some of the __________ particles aimed at gold atoms bounced back, suggesting that a solid mass was at the center of the atom.

Alpha

If element Q has 11 protons and 10 neutrons, its ________________is 11.

Atomic number

If element Q has 11 protons, its ___________is 11.

Atomic number

The Greek philosopher Democritus coined what word for a tiny piece of matter that cannot be divided? b. atom a. Element c. Electron d. Molecule

B atom

Evaporation is the process that changes a substance from a liquid to a gas at temperatures below the substance's _________ point.

Boiling

At sea level, water _________at 100°C.

Boils

The phase change in which a substance changes from a gas directly to a solid c. deposition. The phase change in d. sublimation. a. condensation. b. vaporization.

C deposition

Typically, atoms gain or lose electrons to achieve a. an exchange of energy. b. ionization. C. stable electron configuration. d. vaporization.

C. stable electron configuration.

3. The usefulness of Mendeleev's periodic table was confirmed by a. the discovery of subatomic particles. b. its immediate acceptance by other scientists. C. the discovery of elements with predicted properties. d. the discovery of the nucleus.

C. the discovery of elements with predicted properties.

Which of the following is unique for any given element? a. the number of neutrons c. the number of protons b. the charge on the electrons d. the mass of a neutron

C. the number of protons

Mendeleev gave the name eka-aluminum to a(an) a. compound containing aluminum. b. mixture of aluminum and an unknown element. C. unknown element he predicted would have properties similar to those of aluminum. d. rare isotope of aluminum.

C. unknown element he predicted would have properties similar to those of aluminum.

The phase change that is the reverse of condensation is a. freezing. c. vaporization. b. sublimation. d. melting.

C. vaporization.

In a metal lattice, ___________ are surrounded by a pool of shared electrons.

Cations

The elements cesium (Cs), Barium (Ba), and lutetium (Lu) appear from left to right in Period 6 of the periodic table. Which is the most reactive

Cesium

When Mendeleev organized elements in the periodic table in order of increasing mass elements with similar properties were in the same

Column

Reactive elements such as alkali metals and halogens are found in nature only as _________

Compounds

What type of change occurs when water changes from a solid to a liquid? a. a phase change c. an irreversible change d. both a and b b. a physical change

D:

If the chemical symbol for phosphorus is P, and the chemical symbol for oxygen is O, the molecular compound whose formula is P2O5 is called ____________________

Diphosphorus pentaoxide

If they are two long dashes between two atoms in a structural formula molecules of the compound contain a ________bond

Double

Which of the three subatomic particles-proton, electron, or neutron-has the least mass?

Electron

The main factor that determines whether a molecule will be polar is the relative ________________of each of the atoms forming the covalent bonds

Electronegativity

A polar covalent bond forms when ________are not shared equally between atoms

Electrons

In Bohr's model of the atom, ____________move in fixed orbits around the nucleus

Electrons

When an atom gains or loses energy, some of its ___________may move between energy levels.

Electrons

When an atom gains or loses energy, some of its____________may move between energy levels.

Electrons

Mendeleevs periodic table was useful because it enabled scientists to predict properties of unknown

Elements

During a(an) __________change, a system absorbs energy from its surroundings.

Endothermic

In ionic compounds, the sum of the charges of all the cations and anions must be ____________________

Equal to zero

When potassium, an alkali metal, and fluorine, a halogen, react, they form an ionic compound called potassium___________

Flouride

When all the electrons in an atom are in orbitals with the lowest possible energy, the atom in its ____________ state

Ground

When all the electrons in an atom are in orbitals with the lowest possible energy, the atom is in its _________state.

Ground

Among the elements potassium (Group 1, Period 4), lithium (Group 1, Period 2), and iron (a transition metal)The metallic bonds are likely to be strongest in

Iron

When water boils, some of its molecules have enough ______________to overcome the attraction of neighboring molecules. This allows them to undergo a phase change into a gas.

Kinetic energy

During vaporization, a substance changes from a(an)_________to a(an)_________

Liquid, gas

Mendeleev organized elements in his periodic table in order of increasing

Mass

The ______________ of an isotope is the sum of the number of protons and neutrons in it's nucleus

Mass number

The ____________of an isotope is the sum of the number of protons and neutrons in its nucleus The

Mass number

From left to right across a period in the periodic table, elements become less ____________and more ___________ in their properties

Metallic, nonmetallic

The cathode-ray tube experiment conducted by Thomson showed the beam being deflected downward, proving there were particles in the beam that had a(n) ___________ charge.

Negative

Although they are called _______lights, they can contain any noble gas.

Neon

The difference between a sample of heavy water and regular water is that a hydrogen atom in heavy water has an extra ____________

Neutron

The difference between a sample of heavy water and regular water is that a hydrogen atom in heavy water has an extra____________

Neutron

Protons and ____________ are found in the nucleus of an atom.

Neutrons

Protons and____________ are found in the nucleus of an atom.

Neutrons

The nuclei of isotopes contain different numbers of

Neutrons

nuclei of isotopes contain different numbers of

Neutrons

What determines an elements chemical properties

Number of valence electrons

The pattern of repeating properties of elements revealed in the periodic table is known as the

Periodic law

A(An) ____________ion is a covalently bonded group of atoms that has a positive or negative charge and acts as one unit.

Polyatomic

Neutrons and ______________have almost the same mass.

Protons

Neutrons and _____________have almost the same mass.

Protons

The phase change in which a substance changes from a solid to a gas or vapor without change into a liquid first is

Sublimation

The phase change that is the reverse of deposition is

Sublimation

What can you assume has happened if an electron moves to a higher energy level

The electron has gained energy.

Element 3, lithium, has one valence electron, and element 4, beryllium, has two valence electrons. Element 5 boron has _________valence electrons.

Three

Hydrogen does not have the typical properties of a metal, However, hydrogen is located above Group 1 because it has one ____________________

Valence electron

Hydrogen does not have the typical properties of a metal. However, hydrogen is located above Group 1 because it has one ___________________.

Valence electron

in general the more ___________a metal has, the stronger its metallic bonds will be

Valence electrons

To determine the atomic mass of an element, you would take a(an) ____________ average of the isotopes that make up that element.

Weighted

15. Which statement about electrons and atomic orbitals is NOT true? a. An electron has the same amount of energy in all orbitals. b. An orbital can contain a maximum of two electrons. с. An electron cloud represents all the orbitals in an atom. d. An atom's lowest energy level has only one orbital.

a. An electron has the same amount of energy in all orbitals.

How does increasing the amount of carbon in steel affect its properties? d. Carbon makes the steel softer and easier to cut. c. Carbon makes the steel light enough to use for airplane parts. b. Carbon forms an oxide that protects a. Carbon makes the lattice harder and stronger. the steel from rusting.

a. Carbon makes the lattice harder and stronger.

Which of the following Group 1 elements is the most reactive? c. K (potassium) a. Cs (cesium) d. Na (sodium) b. Li (lithium)

a. Cs (cesium)

Which of the following formulas represents a compound whose molecules contain a triple bond? a. N=N с. O3 b. 0=0=0 d. SO3

a. N=N

Many metals can be drawn into thin wires without breaking because a. cations are still surrounded by electrons when they shift their positions in the lattice. b. metals generally have low melting points. c. when a metal is struck with a hammer, the positions of the anions do not change. d. electrons have fixed positions in a metallic lattice.

a. cations are still surrounded by electrons when they shift their positions in the lattice.

Which subatomic particle has a negative charge? a. electron c. Neutron b. alpha particle d. Proton

a. electron

Which subatomic particle has a negative charge? a. electron с. neutron b. alpha particle d. proton

a. electron

7. As you move from left to right across a period, the number of valence electrons C. increases and then decreases. a. increases. d. decreases. b. stays the same.

a. increases.

As you move from left to right across a period, the с. increases and then decreases. number of valence electrons a. increases. d. decreases. b. stays the same.

a. increases.

Atoms of the most reactive elements tend to have a. one or seven valence electrons. c. four or five valence electrons. b. eight valence electrons. d. no valence electrons.

a. one or seven valence electrons.

Atoms of the most reactive elements tend to have b. eight valence electrons. d. no valence electrons. a. one or seven valence electrons. c. four or five valence electrons.

a. one or seven valence electrons.

What do scientists use to predict the locations of electrons in atoms? a. probability c. geometry b. algebra d. ratios and proportions

a. probability

Which element is found in nature only in compounds? A. sodium с. охудen d. nitrogen b. helium

a. sodium

What does Schrodinger & Heisenberg's electron cloud model describe? a. the most likely locations of electrons in atoms b. the precise locations of electrons in atoms c. the number of electrons in an atom d. the mass of the electrons in an atom

a. the most likely locations of electrons in atoms

What does the electron cloud model describe? a. the most likely locations of electrons in atoms b. the precise locations of electrons in atoms с. the number of electrons in an atom d. the mass of the electrons in an atom

a. the most likely locations of electrons in atoms

According to John Dalton's observations, when elements combine in a compound, a. the ratio of their masses is always the same. b. each element contributes an equal number of atoms. c. their volumes are always equal. d. their masses are always equal.

a. the ratio of their masses is always the same.

According to John Dalton's observations, when elements combine in a compound, a. the ratio of their masses is always the same. b. each element contributes an equal number of atoms. с. their volumes are always equal. d. their masses are always equal.

a. the ratio of their masses is always the same.

The formation of an ionic bond involves the a. transfer of electrons. c. transfer of protons. b. transfer of neutrons. d. sharing of electrons.

a. transfer of electrons.

The elements most likely to form more than one type of ion are the a. transition metals. c. halogens. b. alkali metals. d. alkaline earth metals.

a. transition metals.

12. Which statement accurately represents the arrangement of electrons in Bohr's atomic model? a. Electrons vibrate in fixed locations around the nucleus. b. Electrons travel around the nucleus in fixed energy levels with energies that vary from level to level. c. Electrons travel around the nucleus in fixed energy levels with equal amounts of energy. d. Electrons travel randomly in the relatively large space outside the nucleus.

b. Electrons travel around the nucleus in fixed energy levels with energies that vary from level to level.

Which statement accurately represents the arrangement of electrons in Bohr's atomic model? a. Electrons vibrate in fixed locations around the nucleus. b. Electrons travel around the nucleus in fixed energy levels with energies that vary from level to level. c. Electrons travel around the nucleus in fixed energy levels with equal amounts of energy. d. Electrons travel randomly in the relatively large space outside the nucleus.

b. Electrons travel around the nucleus in fixed energy levels with energies that vary from level to level.

Which halogen is most likely to react? c. I (iodine) a. Br (bromine) d. CI (chlorine) b. F (fluorine)

b. F (fluorine)

Which of the following compounds does NOT contain covalent bonds? a. Н c. CO2 b. NaCl d. H20

b. NaCl

a. Energy b. Water molecules move from their fixed position. flows from the ice to its surroundings. Which of the following statements about ice melting is true? с. Water molecules lose energy. d. The temperature of the ice increases as it melts.

b. Water molecules move from their fixed position.

The unit for atomic mass is c. Pound a. gram d. none of the above b. amu

b. amu

Which of the following gases emit colors when an electric current is applied? c. fluorine and chlorine a. hydrogen and helium d. oxygen and nitrogen b. argon and krypton

b. argon and krypton

Moving from left to right across a row of the periodic table, which of the following values increases by exactly one from element to element? a. isotope number C. atomic mass unit b. atomic number d. mass number

b. atomic number

Moving from left to right across a row of the periodic table, which of the following values increases by exactly one from element to element? b. atomic number d. mass number a. isotope number c. atomic mass unit

b. atomic number

To find the number of neutrons in an atom, you would subtract a. mass number from atomic number. c. atomic number from electron number. b. atomic number from mass number. d. isotope number from atomic number.

b. atomic number from mass number.

J. J. Thomson's experiments provided evidence that an atom a. is the smallest particle of matter. b. contains negatively charged particles. c. has a negative charge. d. has a positive charge.

b. contains negatively charged particles. charge.

You see a structural formula in which the symbols for elements are connected by a long dash. You can assume that the chemical bonds in the compound are a. ionic. c. metallic. b. covalent. d. unstable.

b. covalent.

Which of the following phase changes is an exothermic change? A. sublimation c. Vaporization b. deposition d. Melting

b. deposition

c. four, A member of the boron family has three valence electrons, while a member of the nitrogen family has a. none. d. three. b. five.

b. five.

evaporate During which phase change does the arrangement of water molecules become more orderly? c. Boiling a. melting d. Condensing b. freezing

b. freezing

Alkali metals, alkaline earth metals, and aluminum all form ions with positive charges equal to their a. atomic number. c. period. b. group number. d. atomic mass.

b. group number.

Among the alkali metals, the tendency to react with other substances does not vary among the members of the group. b. increases from top to bottom within the group. с. varies in an unpredictable way within the group. d. decreases from top to bottom within the group.

b. increases from top to bottom within the group.

d. decreases from top to bottom within the group. c. varies in an unpredictable way within the group. b. increases from top to bottom within the group. a. does not vary among the members of the group. Among the alkali metals, the tendency to react with other substances

b. increases from top to bottom within the group.

The name iron(II) indicates that a compound contains a. iron ions with an 11+ charge. c. iron ions with a negative charge. b. iron ions with a 2+ charge. d. two types of iron ions.

b. iron ions with a 2+ charge.

In Niels Bohr's model of the atom, electrons move a. like balls rolling down a hill. с. like popcorn in a popcorn popper. b. like planets orbiting the sun. d. like beach balls on water waves.

b. like planets orbiting the sun.

b. like planets orbiting the sun. a. like balls rolling down a hill. 9 In Niels Bohr's model of the atom, electrons move c. like popcorn in a popcorn popper. d. like beach balls on water waves.

b. like planets orbiting the sun.

2. Fluorine, F, forms a binary ionic compound with lithium, Li, What is the name of this compound? a. fluorine lithide c. lithium fluorine b. lithium fluoride d. fluorine lithium

b. lithium fluoride

a. freezing. d. condensation. The phase change in c. sublimation. which a substance changes from a solid to a liquid is b. melting.

b. melting.

Democritus thought that matter was made of tiny particles a. of earth, air, fire, and water. b. that could not be divided. c. that could be divided. d. that were all round and smooth.

b. that could not be divided.

The molecular compound, sulfur trioxide contains a. three sulfur atoms. c. a polyatomic ion. b. three oxygen atoms. d. an ionic bond.

b. three oxygen atoms.

Which list of elements contains only metals? a. carbon, iodine, tin c. helium, iron, copper b. tin, copper, cesium d. iodine, carbon, argon

b. tin, copper, cesium

Which of the following phase changes is an endothermic change? a. condensation c. Deposition b. vaporization d. Freezing

b. vaporization

Which of the following is NOT part of John Dalton's atomic theory? a. All elements are composed of atoms. b. All atoms of the same element have the same mass. c. Atoms contain subatomic particles. d. A compound contains atoms of more than one element.

c. Atoms contain subatomic particles.

Beryllium, Be, and chlorine, Cl, form a binary ionic compound with a one-to-two ratio of beryllium ions to chloride ions. The formula for the compound is a. Be,Cl. c. BeClz. b. 2BECI. d. Be,Cl2.

c. BeClz.

Which statement about metals is true? a. A metal lattice is extremely rigid. b. The bonds within a metal lattice are weak. c. Electrons in a metal lattice are free to move. d. Generally, metals have a low melting point.

c. Electrons in a metal lattice are free to move.

What is the difference between an atom in the ground state and an atom in an excited state? a. The atom in the ground state has less energy and is less stable than the atom in an excited state. b. The atom in an excited state has one fewer electron than the atom in the ground state. c. The atom in an excited state has more energy and is less stable than the atom in the ground state. d. The atom in an excited state has one more electron than the atom in the ground state.

c. The atom in an excited state has more energy and is less stable than the atom in the ground state.

What can you assume has happened if an electron moves to a higher energy level? a. The atom has become more stable. b. The electron has lost energy. d. The atom has lost an electron. c. The electron has gained energy.

c. The electron has gained energy.

Which statement is true about oxygen-17 and oxygen-18? a. They do not have the same number of protons. b. Their atoms have an identical mass. c. They are isotopes of oxygen. d. The have the same mass number.

c. They are isotopes of oxygen.

Which statement is NOT true about the elements fluorine, chlorine, and iodine? a. They are all halogens. b. They react easily with metals. d. They are all nonmetals. c. They are similar to noble gases.

c. They are similar to noble gases.

Which the following most accurately represents John Dalton's model of the atom? a. a tiny, solid sphere with an unpredictable mass for a given element b. a hollow sphere with a dense nucleus c. a tiny, solid sphere with a predictable mass for a given element d. a sphere that is hollow throughout

c. a tiny, solid sphere with a predictable mass for a given element

When two atoms of the same nonmetal react, they often form a(an) a. ionic bond. c. diatomic molecule. b. polyatomic ion. d. polar molecule.

c. diatomic molecule.

The heat of fusion for water is the amount of energy needed for water to a. freeze. c. melt. d. evaporate b. boil.

c. melt.

The glowing of a neon light is caused by electrons emitting energy as they a. move from lower to higher energy levels. b. collide with other electrons. c. move from higher to lower energy levels. d. collide with the nucleus.

c. move from higher to lower energy levels.

Which of the following is a typical property of an ionic compound? a. low melting point b. poor conductor of electric current when melted c. tendency to shatter when struck d. all of the above

c. tendency to shatter when struck

Which of the following is unique for any given element? c. the number of protons b. the charge on the a. the number of neutrons electrons d. the mass of a neutron

c. the number of protons

Which statement about subatomic particles is true? a. Protons, neutrons, and electrons all have about the same mass. b. Unlike protons or neutrons, electrons have no mass. c. Neutrons have no charge and no mass. d. An electron has far less mass than either a proton or neutron.

d. An electron has far less mass than either a proton or neutron.

Which statement about subatomic particles is true? all have about the same mass. d. An electron has far less с. Neutrons have no charge and no mass. b. Unlike protons or neutrons, a. Protons, neutrons, and electrons electrons have no mass. mass than either a proton or neutron.

d. An electron has far less mass than either a proton or neutron.

To keep them from reacting, some highly reactive elements are stored in c. liquid mercury. a. water. d. Argon b. pure oxygen.

d. Argon

The phase change that is the reverse of sublimation is a. condensation. c. vaporization. b. melting. d. Deposition

d. Deposition

Who provided evidence for the existence of a nucleus in an atom? a. John Dalton c. Democritus b. J. J. Thomson d. Ernest Rutherford

d. Ernest Rutherford

How was Bohr's atomic model similar to Rutherford's model? a. It assigned energy levels to electrons. b. It described electron position in terms of the electron cloud model. c. It described how electrons gain or lose energy. d. It described a nucleus surrounded by space in which electrons orbit the nucleus.

d. It described a nucleus surrounded by space in which electrons orbit the nucleus.

Which statement best describes Rutherford's model of the atom? a. It is like an avocado with the pit representing the nucleus. b. It is like an aquarium with swimming fish representing positive charges. с. It is like a fried egg with the yolk representing the nucleus. d. It is like a racetrack with a positively charged mass around which a track with negative marbles runs.

d. It is like a racetrack with a positively charged mass around which a track with negative marbles runs.

Which statement best describes the properties of sodium chloride? a. Sodium chloride is a malleable solid. b. Solid sodium chloride is a good conductor of electric current. c. Sodium chloride has a low melting point. d. Liquid sodium chloride is a good conductor of electric current.

d. Liquid sodium chloride is a good conductor of electric current.

Which statement about subatomic particles is NOT true? a. Protons and neutrons have almost the same mass. b. Protons and electrons have opposite charges. c. Unlike protons and electrons, neutrons have no charge. d. Protons and neutrons have the same charge.

d. Protons and neutrons have the same charge.

Suppose an atom has a mass number of 23. Which statement is true beyond any doubt? a. The atom has an odd number of neutrons. b. The atomic number is less than 11. c. The atom is not an isotope. d. The number of protons in the nucleus does not equal the number of neutrons.

d. The number of protons in the nucleus does not equal the number of neutrons.

Rutherford's gold foil experiment provided evidence for which of the following statements? a. Negative and positive charges are spread evenly throughout an atom. b. Alpha particles have a positive charge. c. Gold is not as dense as previously thought. d. There is a dense, positively charged mass in the center of an atom.

d. There is a dense, positively charged mass in the center of an atom.

Rutherford's gold foil experiment provided evidence for which of the following statements? a. Negative and positive charges are spread evenly throughout an atom. b. Alpha particles have a positive charge. c. Gold is not as dense as previously thought. d. There is a dense, positively-charged mass in the center of an atom with space around it.

d. There is a dense, positively-charged mass in the center of an atom with space around it.

Which of the following provides the best analogy for an electron in an atomic orbital? a. a bee moving from flower to flower in a garden b. a bird resting on a tree branch c. an ant crawling on the surface of a leaf d. a bee trying to escape from a closed jar

d. a bee trying to escape from a closed jar

The atomic mass of an element is a. the sum of the protons and neutrons in one atom of the element. b. twice the number of protons in one atom of the element. C. a ratio based on the mass of a carbon-12 atom. d. a weighted average of the masses of an element's isotopes.

d. a weighted average of the masses of an element's isotopes.

The atomic mass of an element is a. the sum of the protons and neutrons in one atom of the element. b. twice the number of protons in one atom of the element. c. a ratio based on the mass of a carbon-12 atom. d. a weighted average of the masses of an element's isotopes.

d. a weighted average of the masses of an element's isotopes.

To keep them from reacting, some highly reactive elements are stored in a. water. c. liquid mercury. b. pure oxygen. d. argon.

d. argon.

If a solid piece of naphthalene is heated and remains at 80°C until it is completely melted, you know that 80°C is the a. freezing point of naphthalene. c. boiling point of naphthalene. b. melting point of naphthalene. d. both a and b

d. both a and b

Which element is found in most of the compounds in your body except for water a. iodine с. iron b. potassium d. carbon

d. carbon

The standard on which the atomic mass unit is based is the mass of a a. proton. c. chlorine-35 atom. b. neutron. d. carbon-12 atom.

d. carbon-12 atom.

As you move from left to right across a period, the size of atoms a. increases. с. increases and then decreases. b. stays the same. d. decreases.

d. decreases.

In a polar covalent bond, a. electrons are shared equally between atoms. b. a cation is bonded to an anion. c. electrons are transferred between atoms. d. electrons are not shared equally between atoms.

d. electrons are not shared equally between atoms.

If an atom has 19 protons, 19 neutrons and 18 electrons it is a. an isotope with no charge b. a positively-charged ion c. a negatively-charged ion d. in equilibrium

d. in equilibrium

Mendeleev arranged the known chemical elements in a table according to increasing a. atomic number. c. number of protons. b. number of electrons. d. mass.

d. mass.

Water has a higher boiling point than expected because a. there is so much water vapor in the atmosphere. b. water molecules are not very massive. d. of the strong attractions between polar water molecules. c. hydrogen and oxygen form single covalent bonds.

d. of the strong attractions between polar water molecules.

In a periodic table, a set of properties repeats from a. element to element. c. column to column. b. group to group. d. row to row.

d. row to row.

An alloy that contains mainly iron and carbon is a. sterling silver. c. brass. d. steel. b. bronze.

d. steel.

In an electron dot diagram, the symbol for an element is used to represent a. the nucleus. b. the nucleus and all electrons. c. the nucleus and valence electrons. d. the nucleus and all non-valence electrons.

d. the nucleus and all non-valence electrons.

In the compound MgCl2, the subscript 2 indicates that a. there are two magnesium ions for each ion of chlorine b. the chloride ion is twice the size of the magnesium ion. c. magnesium and chlorine form a double covalent bond. d. there are two chloride ions for each magnesium ion.

d. there are two chloride ions for each magnesium ion.

Metallic bonding is similar to ionic bonding becauseb. electrons are shared between atoms. a. electrons are transferred between atoms. c. the lattice that forms contains anions and cations. d. there is an attraction between positively charged and negatively charged particles.

d. there is an attraction between positively charged and negatively charged particles. drawn into thin wires without

The phase change in which a substance changes from a liquid to a gas is c. condensation. a. deposition. d. vaporization. b. sublimation.

d. vaporization.

The two most reactive groups of elements in the periodic table are the alkali metals and the

halogens

Elements can be classified as metals, nonmetals, and

metalloids

In 1932, James Chadwick was working with radioactive atoms and realized what existed?

neutrons

The pattern of repeating properties of elements revealed in the periodic table is known as the

periodic law

Fertilizers usually contain two elements from Group 15, which are ___________. and ___________

phosphorus. nitrogen

What is the difference between an atom in the ground state and an atom in an excited state? a. The atom in the ground state has less energy and is less stable than the atom in an excited state. b. The atom in an excited state has one fewer electron than the atom in the ground state. с. The atom in an excited state has more energy and is less stable than the atom in the ground state. d. The atom in an excited state has one more electron than the atom in the ground state.

с. The atom in an excited state has more energy and is less stable than the atom in the ground state.

The number of protons in one atom of an element is that element's a. mass number. с. atomic number. b. balanced charge. d. isotope.

с. atomic number.

During a phase change, the temperature of a substance a. increases. с. does not change. b. decreases. d. increases or decreases.

с. does not change.

Ionization energies tend to a. decrease from left to right across a period. b. increase from the top of a group to the bottom. с. increase from left to right across a period. d. decrease from the bottom of a group to the top.

с. increase from left to right across a period.

The water molecule HO is polar because it contains two polar single bonds and a. its molecule has a linear shape. b. molecules that contain polar bonds are always polar. с. its molecule has a bent shape. d. the attractions between water molecules are strong.

с. its molecule has a bent shape.

The tendency of an element to react is closely related to a. its atomic mass. b. attractions between its atoms. electrons in atoms of the element. с. the number of valence d. the ratio of protons to neutrons in atoms of the element.

с. the number of valence neutrons in atoms of the element.

If a molecule contains a triple bond, how many pairs of electrons are being shared? a. one b. two с. three d. none

с. three