Chemistry Test Module 2

Carbon has an atomic number of 6. Therefore, all neutral carbon atoms have ______ and ______.

6 protons, 6 electrons

Gamma radiation has a charge of _____________ and a mass of _______________ amu.

0, 0

One atomic mass unit (amu) is defined as:

1/12th the mass of a carbon-12 atom

Which statements about the ideas of Democritus, Aristotle, and Dalton are true? (Select all that apply) A. Aristotle did not accept Democritus's ideas because he did not believe that empty space could exist. B. Aristotle believed that matter was made up of earth, air, fire, and water. C. Both Dalton and Democritus proposed that matter is composed of extremely small particles. D. Both Dalton and Democritus developed their ideas with the aid of controlled experiments. E. Democritus's atomos were indestructible, but Dalton realized that atoms were made up of subatomic particles.

A, B, C

Which statements about the masses of protons, neutrons, and electrons are true? (Select all that apply) A. The mass of a proton is 1.67 × 10-24 g B. The masses of protons and neutrons are approximately the same. C. The mass of an electron is 1/1840 that of a proton or neutron. D. The mass of a neutron is exactly 1 amu. E. The mass of a proton is exactly 1 amu.

A, B, C

Which describe J.J. Thomson's model of the atom? (Select all that apply) A. It describes the atom as spherical. B. It is sometimes called the "plum pudding model." C. Its electrons reside in various energy levels. D. Its electrons surround a small, dense nucleus. E. Its positive charge is uniformly distributed.

A, B, E

Which statements about the charge and mass of subatomic particles are true? (Select all that apply) A. The mass of a neutron is very slightly greater than the mass of a proton. B. Electrons and protons have equal and opposite charges. C. Protons are negatively charged. D. The mass of an proton is 1/1840 that of an electron. E. A neutron is electrically neutral.

A, B, E

Which are characteristics of Rutherford's model of the atom? (Select all that apply) A. electrons that surround the nucleus in defined energy levels B. a small nucleus that contains almost all of the atom's mass C. a small nucleus that contains the atom's positive charge D. a uniformly-distributed positive charge E. electrons that are held within the atom by their electrical attraction to the nucleus

B, C, E

Many early philosophers concluded that matter ______. (Select all that apply) A. was composed of atoms B. was composed of earth, water, air, and fire C. was made up of elements such as hydrogen and carbon D. could be endlessly divided into smaller and smaller pieces

B, D

Which of these statements about atoms are true? (select all that apply) A. The nucleus contains the protons and electrons. B. Most of the mass of an atom is in its nucleus. C. A nucleus occupies only about one-tenth of the volume of the atom. D. Atoms are mostly empty space containing fast-moving electrons. E. The number of neutrons is always equal to the number of protons.

B, D

A cathode-ray tube (Select all that apply) A. can be used to see atoms. B. depends on the use of a vacuum pump for its function. C. includes a tube that contains the inert gas nitrogen. D. was used to study the relationship between mass and charge. E. has metal electrodes connected to opposite ends.

B, D, E

Democritus proposed that matter was made up of atoms, which could not be ____________________, _________________, or further divided.

Created, Destroyed

When did scientists begin to be able to answer questions about the composition of the atom? A. early 1800s B. late 1700s C. late 1900s D. late 1800s

D

Which statement best describes the design of Rutherford's gold foil experiment? A. A sample of gold was heated so much that it emitted alpha particles. Researchers noted the deflection of the alpha particles. B. Alpha particles were fired through gold foil and researchers noted how many of them made it through the foil without being absorbed. C. Electrodes were attached to some gold foil and the resulting electrons were fired through a cathode-ray tube. Their deflection was noted. D. Alpha particles were fired through gold foil. Researchers noted whether the particles were deflected and by how much.

D

What is the smallest particle of an element that retains the properties of the element?

atom

The atomic mass of an element is not a whole number because the atomic mass is the weighted __________________ mass of the isotopes of that element, and isotopes have different ________________________.

average, relative abundances

A high-speed electron with a 1- charge that is emitted during radioactive decay is called a(n) _______________ _________________.

beta particle

Which is a high-speed electron with a 1- charge that is emitted during radioactive decay?

beta particle

Radiation that is deflected toward a positively charged plate when directed between two electrically charged plates is called ________________ ___________________.

beta radiation

Dalton's atomic theory supports the law of conservation of mass because in his theory, atoms are not created, ____________, or divided in a chemical reaction. Therefore, the total ____________________before and after the reaction does not change.

detroyed, mass

Thomson's cathode ray-tube experiments led to the discovery of which subatomic particle?

electron

Thomson's cathode-ray tube experiments led him to identify the first subatomic particle, the _______________________..

electron

The type of equation shown here is called a(n) ______. 22688Ra ⇝ 22286Rn + α

nuclear equation

A reaction that involves a change in an atom's nucleus is called a(n) ________________.

nuclear reaction

What is any reaction that involves a change in an atom's nucleus?

nuclear reaction

What is the extremely small, dense center of an atom that contains the atom's positive charge and almost all of its mass?

nucleus

The rays and particles—alpha and beta particles and gamma rays—that are emitted by radioactive materials are called _______________________.

radiation

The change of one or more substances into new substances, involving only an atom's electrons, is a(n)________________ reaction. A reaction that may involve the change of one element into another is a(n) ______________reaction.

Chemical, Nuclear

A negatively charged, fast-moving particle with an extremely small mass that is found in all forms of matter and moves through the empty space surrounding an atom's nucleus is called a(n)__________________.

Electron

Aristotle did not believe that ____________ ______________ could exist.

Empty Space

Who did the gold foil experiment?

Ernest Rutherford

The atomic number is equal to the number of ____________in an atom. It is also equal to the number of ____________ in an atom.

Protons, Electrons

The subatomic particles located in the nucleus of the atom are the ________________ and neutrons. The subatomic particles that are found in the space surrounding the nucleus are the ________________________.

Protons, Electrons

The process in which some substances spontaneously emit radiation is called ____________________.

Radioactivity

In the late 1800s, scientists directed radiation between two electrically charged plates. They were able to identify _____________ different types of radiation based on their____________ __________________.

Three, Electric charge

A spontaneous process in which unstable nuclei lose energy by emitting radiation is called ________________________________.

radioactive decay

The number that identifies each isotope of an element and is the sum of the number of protons and neutrons in the nucleus is the _______________number.

mass

The primary factor in determining an atom's nuclear stability is its ratio of ___________ to __________.

neutrons, protons

A type of equation that shows the atomic number and mass number of the particles involved in a nuclear reaction is called a(n) _______________ ______________.

nuclear equation

It was not until nearly 1900 that scientists began to be able to answer questions about the composition of the ____________________.

atom

Radiation that originates from the cathode and travels to the anode of a cathode-ray tube is called a(n) ___________________ ___________________.

Cathode ray

Gamma radiation has a mass of ____________amu and a charge of ___________.

0, 0

The mass and charge of a beta particle are, respectively, ______.

1/1840 amu, 1-

Alpha radiation consists of alpha particles, which have a charge of ________________ and a mass of _________________ amu.

2+, 4

What was Millikan able to determine through his oil-drop experiments?

Charge and Mass of an electron

Different atoms combine in simple whole-number ratios to form compounds. A. Dalton B. Dalton and Democritus C. Aristotle

A

In nature, the relative abundance of each isotope of an element is ______. A. almost always constant B. unpredictable and must be determined by experiment C. always constant or always different, depending on the element D. almost always different

A

In nuclear reactions, but not chemical reactions, A. an element may change into another element. B. only the electrons of the atoms are involved. C. atoms are rearranged but not created, destroyed, or changed. D. one or more substances change into different substances.

A

Relative charge = 1+, relative mass = 1 : A. Proton B. Neutron C. Electron

A

The mass of an electron is ______. A. 9.1 × 10-28 g B. 0.00054 g C. 1 amu D. 1.7 × 10-24 g

A

What name is given to John Dalton's ideas about matter, which resulted from many careful measurements and observations? A. Dalton's atomic theory B. Dalton's law C. the plum pudding model of the atom tD. he law of conservation of mass

A

Several thousand years ago, people sought after the truth about the nature of matter by ______. (Select all that apply) A. thinking intellectually B. formulating explanations based on life experiences C. asking questions and testing them by scientific methods D. performing controlled experiments

A, B

Democritus's ideas were not accepted at the time he proposed them (or for thousands of years afterward) because (Select all that apply) A. Aristotle, one of the most influential Greek philosophers, did not support them. B. Aristotle had superior evidence for his competing ideas. C. he was unable to back up his ideas with evidence from controlled experiments. D. science as we know it did not exist.

A, C, D

In the late-1800s experiments in which scientists began researching radioactivity, (Select all that apply) A. three different types of radiation were detected. B. each type of radiation behaved differently based on its mass. C. negatively charged radiation was deflected towards the positively charged plate. D. radiation was directed between two electrically charged plates. E. electrically neutral radiation was not deflected towards either plate.

A, C, D, E

Which statement best describes the results of Rutherford's experiments? (Select all that apply) A. Most alpha particles went straight through the gold foil. B. Most alpha particles were absorbed by the gold foil. C. Several particles were deflected straight back toward the source. D. A few particles were deflected at large angles.

A, D

Which statements are part of Dalton's atomic theory? (Select all that apply) A. Atoms of a specific element are different from those of another element. B. Atoms of the same element may have different masses and slightly different properties. C. Matter is made up of earth, air, fire, and water. D. Atoms are indivisible and indestructible. E. Atoms are made up of electrons, protons, and neutrons. F. In a chemical reaction, atoms are separated, combined, or rearranged.

A, D, F

Number these steps of Rutherford's gold foil experiment in order from first (one) to last (four). A. A zinc-sulfide-coated screen produced a flash when struck by an alpha particle B. A narrow beam of alpha particles was aimed at a thin sheet of gold foil C. Researchers could then determine if atoms in the gold foil deflected the alpha particles D. Researchers noted where the flashes occurred

A. 2, B. 1, C. 4, D. 3

What were J.J. Thomson's cathode-ray tube experiments in the late 1890s designed to determine?

Charge-to-mass ratio of an electron

Which type of radiation is deflected towards a negatively-charged plate when radiation from a radioactive source is directed between two electrically charged plates?

Alpha Radiation

Which is a particle with two protons and two neutrons that has a 2+ charge, is equivalent to a helium-4 nucleus, and is represented by the symbol α?

Alpha particle

Radiation that is deflected towards a negatively-charged plate when radiation from a radioactive source is directed between two electrically charged plates is called ________________ _________________.

Alpha radiation

Rutherford conducted an experiment to see if ______________ particles would be deflected as they passed through _________________ ___________________.

Alpha, gold foil

Matter is made up of tiny particles that are indestructible and indivisible. A. Dalton B. Dalton and Democritus C. Aristotle

B

Relative charge = 0, relative mass = 1 A. Proton B. Neutron C. Electron

B

Democritus proposed that (Select all that apply) A. matter consisted of earth, fire, air, and water. B. the atoms that made up matter could not be created, destroyed, or further divided. C. matter was made up of tiny particles called atomos (atoms). D. matter was not infinitely divisible. empty space could not exist.

B, C, D

Which type of radiation is deflected toward a positively-charged plate when radiation from a radioactive source is directed between two electrically-charged plates?

Beta Radiation

According to Dalton's atomic theory, A. different atoms of the same element may have different masses. B. atoms are made up of electrons surrounding a nucleus. C. atoms are separated, combined, or rearranged in a chemical reaction. D. matter is composed of earth, air, water, and fire.

C

Matter is made of earth, air, fire, and water. A. Dalton B. Dalton and Aristotle C. Aristotle

C

Relative charge = 1-, relative mass = 1/1840 A. Proton B. Neutron C. Electron

C

The particles that make up alpha radiation have a ______. (Select all that apply) A. mass of 11840 amu B. charge of 4+ C. a mass of 4 amu D. charge of 1- E. mass of 2 amu F. charge of 2+

C, F

John Dalton's ideas about matter, which arose from his many experiments in which he studied the mass ratios of elements involved in chemical reactions, are collectively known as _________________ _______________ ________________.

Dalton's Atomic Theory

Several thousand years ago, science as we know it today ______.

Did not exist

What term is used for atoms with the same number of protons but different numbers of neutrons?

Isotope

Who created the plum pudding model?

JJ Thomson

A particle with two protons and two neutrons that has a 2+ charge, is equivalent to a helium-4 nucleus, and is represented by the symbol α is called a(n)_____________ ___________________.

alpha particle

Radioactive atoms emit radiation because their nuclei ______.

are unstable

J.J. Thomson's cathode-ray tube experiments in the late 1890s were designed to determine the ratio of an electron's ___________________ to its _____________________.

charge, mass

Through his oil-drop experiments, Millikan was able to determine the ___________ and ________________ of an electron.

charge, mass

A(n) ______________ is a negatively charged, fast-moving particle with an extremely small mass that is found in all forms of matter and moves through the empty space surrounding an atom's nucleus?

electron

Many early philosophers concluded that matter was composed of four "elements": earth, air, ___________________, and __________________.

fire, water

Which is high-energy radiation that has no electrical charge and no mass and is not deflected by electric or magnetic fields?

gamma radiation

High-energy radiation that has no electrical charge and no mass and is not deflected by electric or magnetic fields is called a(n)_____________________

gamma ray

The mass of an electron is 1/1840 of the mass of a(n) ___________________ atom.

hydrogen

Atoms with the same number of protons but different numbers of neutrons are called __________________

isotopes

Nuclei that lose energy by emitting radiation through radioactive decay do so because they are ___________________. This decay continues until the nuclei become ___________.

unstable, stable