Intro to Physics and Chemistry:Ch. 4
Neutrons contribute to an atom's atomic number, but not to its mass number.
False
The chemical properties of an element depend on the number and arrangement of the protons in its atoms.
False
A neutral atom that contains 11 protons also contains 11 electrons.
True
When electrons gain additional energy, they move farther away from the nucleus.
True
All neutrons A. are electrically neutral B. have a mass equal to an electron C. are electrically positive D. are located outside the nucleus
a
As a result of his experiment, Rutherford proposed that an atom has A. a dense, positively charged nucleus B. a dense, negatively charged nucleus C. a neutral nucleus surrounded by negatively charged electrons D. a neutral nucleus surrounded by positively charged particles
a
Rutherford's experiment demonstrated that A. atoms have a positively charged nucleus B. atoms are present in gold foil C. Thomson's atomic model was correct D. atoms are positively charged
a
The charge of the nucleus of an atom is a. positive b. negative c. neutral d. none of the above
a
The formula for calculating the maximum capacity of an electron energy level is A. 2n2 B. n2 C. 2n3 D. 3n2
a
fast-moving, positively charged particles
alpha particles
believed that matter could be divided forever
aristotle
thought that all substances were made of only four elements—earth, air, fire, and water
aristotle
To calculate the number of neutrons in an atom, the ___ number must be subtracted from the mass number.
atomic
8. The number of protons in the nucleus of an atom is indicated by the a. element number b. atomic number c. mass number d. atomic weight
b
According to the Rutherford model of the atom, electrons are held in an atom A. in the nucleus B. by the attraction of the positively charged nucleus C. scattered among positive charges D. by the attraction of the negatively charged nucleus
b
An isotope form of an element is a form of the element with a different number of ___ in the nucleus a. protons b. neutrons c. electrons d. quarks
b
In Niels Bohr atom model, electrons move like A. balls moving down a hill B. planets orbiting the sun C. popcorn in a popcorn popper D. beach balls on water waves
b
The atomic theory of matter was developed by a. Bohr b. Dalton c. Rutherford d. Thomson
b
The electron was discovered by A. Dalton B. Thomson C. Rutherford D. Bohr
b
The level of an electron in an electron cloud A. is impossible to determine B. depends on how much energy the electron has C. depends on the charge of the electron D. depends on the mass of the electron
b
The maximum capacity of the 3rd energy level A. 9 B. 18 C. 32 D. 36
b
The nucleus of an atom contains A. protons and electrons C. electrons and neutrons B. protons and neutrons D. only neutrons
b
The word atom comes from the Greek word atomos, meaning A. matter B. indivisible C. mass D. volume
b
The diagrams of an atom that look like a solar system with planets revolving around a sun was developed by a scientist named ___.
bohr
If an isotope of sulfur has 16 protons, 17 neutrons, and 16 electrons, its mass number is A. 16 B. 17 C. 33 D. 49
c
The atomic number of an element indicates the A. sum of protons plus neutrons B. sum of protons plus electrons C. number of protons D. number of neutrons
c
The smallest piece of matter was named "atom" by A. Socrates B. Dalton C. Democritus D. Hippocrates
c
The sum of the protons and neutrons in the nucleus of an atom is indicated by the a. element number b. atomic number c. mass number d. weight number
c
Which is NOT a characteristic of the modern atomic model? A. Electrons surround the nucleus B. An atom is neutral C. The nucleus takes up most of the atom D. The nucleus is positively charged
c
Which scientist stated that the nucleus had a positive charge? A. Thomson B. Bohr C. Rutherford D. Democritus
c
Within the electron cloud, electrons are arranged in A. no particular order C. energy levels B. groups of 4 D. groups of 6
c
who discovered the neutron
chadwick
Almost all of the mass of an atom is found A. outside the nucleus C. in the energy levels B. in the electron cloud D. in the nucleus
d
An element has an atomic number of 4 and a mass number of 9. The number of neutrons in the nucleus of this element is A. 2 B. 3 C. 4 D. 5
d
Atoms of the same element may differ in their numbers of A. protons C. protons plus electrons B. electrons D. neutrons
d
The passage of an electric current through a gas was used by J.J. Thomson in experiments that led to the discovery of the a. proton b. quark c. neutron d. electron
d
The theory that electrons are located in specific energy levels was first proposed by a. Bohr b. Dalton c. Rutherford d. Thomson
d
Which of the following terms means "indivisible"? a. wave b. electron c. quark d. atomos
d
___ proposed the theory that all matter is made up of individual particles called atoms.
dalton
___ said that atoms of the same element are exactly alike and atoms of different elements are different.
dalton
proposed the theory that all matter is made up of individual particles called atoms, which cannot be divided.
dalton
said that compounds have a fixed composition.
dalton
stated that the ratio of the masses of the elements in each compound was always the same
dalton
studied the behavior of gases in air
dalton
___ is the first scientist that said that matter cannot be divided into smaller pieces forever.
democritus
believed that all matter consisted of extremely small particles that cannot be divided
democritus
A(n) ___ is the arrangement of electrons in the orbitals of an atom.
electron configuration
According to modern atomic theory, ____ can move from one energy level to another.
electrons
Dalton's theory said that most of the atom's mass is in the nucleus.
false
Positive alpha particles were shot through ____ foil.
gold
when all the electrons in an atom have the lowest possible energies
ground state
___ evidence is gathered without seeing an object.
indirect
Atoms of the same element that have the same number of protons, but different number of neutrons are called ____.
isotopes
What is the one thing that determines the identity of an atom?
its number of protons
The possible energies that electrons in an atom can have are called energy ___.
levels
Scientist use the electron cloud model to describe the possible ___ of electrons around the nucleus.
location
Thomson said that atoms have a ___ charge.
neutral
The ___ is the neutral subatomic particle that is found in the nucleus of an atom.
neutron
An isotope of an element has the same atomic number, but a different mass number because they have different number of ___.
neutrons
Positive alpha particles were shot through foil to discover the ____.
nucleus
The atomic _____ of an element never changes.
number
A(n) ___ is a region of space around the nucleus where an electron is likely to be found.
orbital
A scientist had a theory that all particles in the nucleus had a ___ charge.
positive
The atomic number of an element is equal to the number of ___ in an atom of an element.
protons
The mass number of an atom is the sum of the ___ in the nucleus of an atom.
protons and neutrons
what two subatomic particles have the same mass
protons and neutrons
The scientist that discovered the nucleus is ___.
rutherford
__ stated that the positive charge of an atom is concentrated in a nucleus.
rutherford
___ asked a student named Ernest Marsden to shoot alpha particles through a thin sheet of gold.
rutherford
The experiments performed by ___ provided the first evidence that atoms are made of even smaller particles.
thomson
The scientist that discovered the "corpuscles" of an atom is ___.
thomson
The scientist that said that gases gave off rays that had a negative charge is ___.
thomson
___ provided us with the "plum pudding" model of the atom showing that negative and positive charges were spread evenly throughout the atom.
thomson
who discovered electrons
thomson
Particles smaller than an atom are called subatomic particles.
true
Thomson's theory was summarized by the "plum pudding" model.
true
