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WorksheetsAtomic Structure Review HW
Total questions: 64
Worksheet time: 11mins
Democritus named the smallest particles of matter (a) because they could not be divided.
Dalton's theory suggests that all matter is made up of individual particles called (a) , which cannot be divided.
Which of the sentences below does not represent main points of Dalton's theory of atoms.
All elements are composed of atoms.
In a particular compound, atoms of different elements always combine the same way.
All atoms have the same mass.
Objects with like electric charges __________.
attract
repel
reflect
deflect
Objects with opposite electric charges __________.
attract
repel
reflect
deflect
Thomson concluded that the particles in the glowing beam had a(n) (a) charge because they were attracted to a positive plate.
Which of the sentences below does not describe Thomson's model of the atom.
An atom is filled with positive matter.
An atom is mostly space with a small nucleus.
Negative charges are scattered throughout an atom.
This model is used today for studying atoms.
Dalton
Thomas
Rutherford
Bohr
J.J. Thomson’s experiments provided the first evidence of __________.
atoms
a nucleus
subatomic particles
elements
The concept of an atom as a small particle of matter that cannot be divided was proposed by the ancient Greek philosopher, Democritus.
True
False
Which of the subatomic particles has a positive charge?
(a)
Which of the properties below vary among subatomic particles.
color
location in an atom
charge
Which of these expressions accurately compares the masses of neutrons and protons.
mass of 1 neutron = mass of 1 proton
mass of 2000 neutrons = mass of 1 proton
mass of 1 electron = mass of 1 proton
Two atoms of the same element can have different numbers of protons.
True
False
The (a) number of an element equals the number of protons in an atom of that element.
Two different elements can have the same atomic number.
True
False
The (a) number of an atom is the sum of the protons and neutrons in the nucleus of that atom.
number of neutrons = mass number - (a)
Every atom of a given element has the same number of protons and (a) .
Every atom of a given element does not have the same number of (a) .
(a) are atoms of the same element that have different numbers of neutrons and different mass numbers.
All oxygen atoms have 8 protons. How many neutrons is in an atom of oxygen-18?
10 neutrons
8 neutrons
18 neutrons
Isotopes of oxygen have different chemical properties when reacting with hydrogen.
True
False
In which way to isotopes of an element differ?
number of electrons in the atom
number of protons in the atom
number of neutrons in the atom
net charge of the atom
Of the three subatomic particles that form the atom, the (a) has the smallest mass.
Electrons will move to a higher energy level if they (a) energy.
Electrons will release energy when they move to a __________ energy level.
higher
lower
Which one of these options tells how Bohr's model of the atom differed from Rutherford's model.
Bohr's model focused on the nucleus.
Bohr's model focused on the protons.
Bohr's model focused on the electrons.
When an atom gains or loses energy, its electrons can move from one (a) to another.
When electrons release energy, some of the energy may be released as visible light.
True
False
Bohr's model was correct in assigning energy levels to electrons.
True
False
When trying to predict the locations and motions of electrons in atoms, scientists must work with __________.
precision
probability
accuracy
A(n) (a) is a visual model of the most likely locations for the electrons in an atom.
According to Bohr's model of the atom, which of the following can happen when an atom gains energy?
An atom returns to its ground state.
A neutron can be changed into a proton.
A proton can move to a higher energy level.
An electron can move to a higher energy level.
How does the modern atomic theory describe the location of electrons in an atom?
Electrons move randomly in space around the nucleus.
Electrons can be described as a cloud based on probable locations.
Electrons orbit the nucleus in the same way that planets orbit the sun.
Electrons move in a spiral pattern if increasing distance from the nucleus.
What is meant when an atom is said to be in its ground state?
There is no net charge on the atom.
The number of protons equals the number of neutrons.
The atom’s electrons all have the lowest possible energies.
It is the isotope with the least number of neutrons.
An orbital is a region of space around the nucleus where an electron is likely to be found.
True
False
How many energy levels are needed for a lithium atom's three electrons when the atom is in its ground state?
1
2
3
An excited state is less stable than a ground state.
True
False
Which of the following statements is not true when all of the electrons in an atom are in orbitals with the lowest possible energies.
The electrons are in the most stable configuration.
The electrons are in an unstable configuration.
The atom is in its ground state.
How many electrons are in the outermost (valence) level of oxygen?
(a)
How many electrons are in the outermost (valence) level of sodium?
(a)
How many electrons are in the outermost (valence) level of fluorine?
(a)
How many electrons are in the outermost (valence) level of helium?
(a)
How many electrons are in the outermost (valence) level of magnesium?
(a)
the basic unit of matter
(a)
a unique number for each element that equals the number of protons in an atom of that element
(a)
a negatively charged subatomic particle that is found in the space outside of the nucleus of an atom
(a)
a visual model of the most likely locations for the electrons in an atom
(a)
the arrangement of electrons in the orbitals of an atom
(a)
a diagram that shows the element symbol surrounded by dots
(a)
a pure substance that cannot be broken down into simpler substances by ordinary chemical means
(a)
a particular region where electrons can orbit a nucleus
(a)
a state in which all the electrons in an atom have the lowest possible energies
(a)
atoms with the same number of protons but a different number of electrons
(a)
atoms of a given element that have different numbers of neutrons and different mass numbers
(a)
the sum of the number of protons and neutrons in the nucleus of an atom
(a)
a neutral subatomic particle that is found in the nucleus of an atom
(a)
the dense, positively charged mass located in the center of an atom
(a)
a region of space around the nucleus where an electron is likely to be found
(a)
a chart that organizes the chemical elements based on their properties
(a)
a positively charged subatomic particle that is found in the nucleus of an atom
(a)
capable of releasing radiation
(a)
electrons found in the outermost energy level of an atom
(a)
