Chapter 3 Flashcards
All atoms of a given type are ________ to each other.
similar
What 3 physical characteristics of all atoms are known with a great deal of certainty?
size, shape, and mass
Atoms are incredibly small but they differ in _____ and _______.
size and mass
If atoms can break apart, they must be made of something ______ than an atom.
smaller
___________ are small particles which serve as fundamental building blocks for all atoms.
Subatomic particles
All atoms are made up of very small particles called ______ _______.
subatomic particles
_______ have a negative charge.
Electrons
_______ have a positive charge.
Protons
______ have NO charge.
Neutrons
The subatomic particles can be distinguished from each other based on their _____ and ______.
charge and size
What is the charge associated with an electron?
negative
Why did it take so long to find the neutron?
Neutrons don’t have a formal charge
What is the overall charge of an atom?
neutral
In order for an atom to have a neutral charge, it must contain the same number of _____ and _______.
protons and electrons
Electrons travel from the ______ electrode and move toward the ______ one.
negative (cathode);
positive (anode)
Robert Millikan was able to calculate the _________ of an electron.
charge / mass ratio from the experimental data
Protons move toward the ______ electrode.
negative
Protons are approximately ____ more ______ than electrons.
1800 times more massive
What did scientists NOT KNOW about atoms and subatomic particles after the discovery of radioactivity?
They didn’t know how they were organized within the structure and they didn’t know about neutrons.
What is the calculated mass, in grams, of a proton?
1.673 x 10^-24g
Ernest Rutherford proposed that most of the mass of an atom was found where?
in the nucleus
Since the total mass of all the electrons in an atom is negligible, the mass of an atom is determined by the number of ____ and ______.
protons and neutrons
Protons and neutrons are much ______ than electrons.
heavier
According to the modern atomic model, most of the volume of an atom is ______ space.
empty
The volume or size of an atom is basically determined by the movement of ______.
electrons
The total mass of an atom is basically found in the _____ of an atom.
nucleus
The size or volume of an atom is determined by the ________.
area swept out by the electrons, which is mostly empty space.
TRUE or FALSE:
Large atoms are always more massive than small ones.
false
The nucleus of an atom has a net ______ charge.
positive
The overall charge of an atom is ______.
neutral
The mass of an atom is determined by the _______ and the size of the atom is determined by the ______.
nucleus;
electrons and their movement
The relative number of _____________ accounts for the observed differences in atoms.
subatomic particles
An uncharged atom must always have equal numbers of _____ and ______.
protons and electrons
Whenever an uncharged atom has one more proton than another atom of a different type, it must also have one more _______.
electron
Carbon atoms have 6 protons, therefore they must have _____ electrons.
6
If two atoms represent two different elements, they must have a different number of ______.
protons
The ________ is the counted number of protons in the nucleus of an atom and is a unique identifier for each element.
atomic number
The atomic number is a description of the number of _______ in the nucleus of at atom.
protons
If 2 atoms have different atomic numbers, they must be atoms of different _____.
elements
An element can be _______ by it’s atomic number.
identified
If Uranium if the element 92, how many electrons are found in a Uranium atom?
92
TRUE or FALSE:
An atomic number of 2.5 is an allowed value for certain atoms.
false
The ________ of an atom is a whole number that describes the total number of protons and neutrons in the nucleus of an atom.
mass number
The mass number is also referred to as:
the A number
The sum of protons and neutrons in a nucleus is referred to as the ____________.
mass number
What is the mathematical equation to find the mass number of an element?
mass number (A) = number of protons (p) + number of neutrons (n)
Only two numbers are needed to specify the complete subatomic composition of an atom. These two numbers are the _____ and ____ number.
mass and atomic
The notation used for showing the mass number and atomic number of an atom is what?
- Use the proper elemental symbol.
- Place the mass number as a superscript at the left hand side of the symbol.
- Place the atomic number as a subscript at the left hand side of the symbol.
Atoms of the same element are _______.
similar
Explain why carbon atoms with mass number 13 and 14 are both considered carbon atoms.
They all have the same number of protons - this is what determines which element it is. When the mass number is different, it’s an isotope of that atom.
______ are atoms of the same element having different numbers of neutrons.
Isotopes
TRUE or FALSE:
The atomic number of an atom can be larger than it’s mass number.
false
TRUE or FALSE:
All naturally occurring elements have more than one natural isotope.
false
TRUE or FALSE:
The actual mass of an atom and the mass number of an atom are the same.
false
When a chemist determines the mass of an element, he/she is taking the _______ mass of all the naturally occurring isotopes found in the sample.
average
What two pieces of information are required to determine the average mass of an element?
mass of isotopes and relative abundance
When determining an average mass of an element, what factor might have a great deal of variability?
relative abundance of isotopes
Why do chemists need to know the average mass of an element and what does it really mean?
Using the average, he/she can immediately calculate the total number of atoms found in the sample. Moreover, the purity of the sample can be determined quickly by knowing what the given volume should weigh.
Why is knowing the average mass of all isotopes more important, to chemists, than knowing the individual masses of each isotope?
Chemists usually work with all naturally occurring isotopes at the same time.
The mass of each isotope is determined by a __________________.
mass spectrometer
The reference isotope used for all mass calculations is __________.
carbon-12
What is the scale used to describe the mass of each isotope?
atomic mas units or amu
Why do chemists use the amu scale rather than the metric gram scale for describing the mass of atoms?
The amu scale doesn’t involve very small fractions of mass like the gram scale would, for atoms.
TRUE or FALSE:
The atomic mass and the mass number are the same thing and have the same meaning.
false
Where is the atomic mass located on the periodic table?
below the element
How do you calculate the average atomic mass?
amu mass x relative abundance (in decimal form), then add the products and round to the appropriate number of significant figures
TRUE or FALSE:
Most of the naturally occurring elements were discovered in the 20th century.
false
TRUE or FALSE:
Most of the synthetic or artificial elements were discovered in the 20th century.
true
TRUE or FALSE:
If there are 88 naturally occurring elements with element 92 being the largest by mass, then some of the elements with atomic numbers smaller than 92 must be man-made.
true
Dmitri Mendeleev and Julius Lothar Meyer began a project to ________ the elements.
organize
The first level of organization involved aligning the known elements by _____.
mass
The properties of the elements tend to repeat themselves in intervals of ______.
eight (8)
________ refers to the repeating pattern of similar properties in intervals of 8. This phenomenon is called the periodic nature of the elements.
Periodicity
The periodic table is simply a chart which organizes the ______ in groups with similar ______ and _______ properties.
elements;
physical;
chemical
Elements in the modern periodic table are listed according to ______________.
increasing atomic number
The rows in the periodic table are called ________ because each new row is started at the logical location for a repeating pattern.
periods
The columns in the periodic table are called ______.
groups
What part of the atom is involved in the interaction with other atoms?
the outer surface where the electrons are located
Quantum mechanics is the applications of ______ mechanics to the behaviors of ______.
light;
electrons
In the Bohr model, electrons can be compared with _____ in the solar system.
planets
_______ is used to define a package or quantity of energy sufficient to promote electron movement.
Quantum
According to Bohr’s atomic model, electrons move around the nucleus in orbits. Describe 3 different features of the electrons in Bohr’s model orbits when compared with planets.
Electrons have 3-dimensional or spherical orbits. Electrons can jump into other orbits, when given energy. Upon relaxing back into the original orbit, light is given off.
Modern atomic theory suggests that the exact ______ of an electron cannot be determined.
location
A _________ id the region in space where an electron would most likely be found.
probability region
Electrons, according to modern atomic theory, can be grouped into energy levels similar to the Bohr model. These energy levels are called ________.
shells
The ____________ is an integer value that describes the energy level in which a set of electrons with similar energy reside.
principle quantum number
Each energy level in the Bohr atom is identified by the quantum numbers which is a whole number greater than _______.
zero
The larger the quantum number for an electron orbit, the ______ it is from the nucleus.
farther
A shell number if the same as the _________.
energy level or principle quantum number
Electron shells have an ________ distance from the nucleus.
approximate
TRUE or FALSE:
An energy level of 3 can hold more electrons than an energy level of 4.
false
Electrons tend to fill the ______ energy levels when in the ground state.
lowest
TRUE or FALSE:
The absolute energies of electrons in the same energy levels of different elements are not necessarily the same.
true
What is the maximum number of electrons that can be placed into a 5th shell?
50
What is the mathematical model for shell capacity?
2n^(2), where “n” is the shell quantum number
The __________________ refers to energy sublevels.
second quantum number
The second quantum number for an electron is called the ________.
subshell or sub-energy shell
TRUE or FALSE:
Electrons in the atoms of two different elements may have the same address notation.
true
TRUE or FALSE:
Two different electrons in a given atom may have the same address notation.
false
The third quantum number is called the _______, because a solution in Schrodinger’s equation using all three quantum numbers gives a unique 3D shape and direction when plotted on a graph.
orbital
How many possible 3rd quantum numbers or orbitals are allowed for an f sublevel?
7
The ______ is the region in space, about the atom, where electrons are usually located.
orbital
What is the maximum number of electrons a 5d shell can hold?
10
What is the maximum number of electrons a 4s shell can hold?
2
What is the shorthand notation for the location of 2 electrons in the 4th energy level, p sublevel?
4p^2
The fourth quantum number is called the _______.
spin number
If two electrons occupy the same orbital, they must be spinning in ______ directions.
opposite
In writing an electron configuration, how do you know when you have used all of the electrons available for a given element?
the superscript numbers will add up to the atomic number
What ending electron configuration would you predict for the elements in group I A on the periodic table?
s1
The ___________ of an element are the electrons found in the outer most sublevel of the element according to the electron configuration using Aufbau’s principle.
distinguishing electrons
The size of the atoms in terms of _____ tends to increase from left to right, top to bottom.
mass
The size of atoms in terms of ______ tends to increase from right to left, top to bottom.
volume
According to quantum mechanics, what is the maximum number of electrons that may occupy the 4s orbital?
2
What group is associated with the alkaline earth metals?
IIA
Indicate which of the following statements is false:
A. The size (diameter) of an atom depends on the movement of the electrons.
B. Each region outside the nucleus contains electrons.
C. The atom is mostly empty space.
D. The total charge of an atom is found in it’s nucleus.
E. more than one statement is false.
F. No statement is false
The total charge of an atom is found in the nucleus.
Positive charge is in the nucleus, but negative charge is in the electron cloud.
Which of the following accurately describes a neutron? A. has a positive charge B has a negative charge C. has no charge D. was discovered by James Chadwick E. more that one correct response F. no correct response
more than one correct response.
has no charge,
discovered by James Chadwick
What is the maximum number of electrons that can occupy the 3rd shell?
18
TRUE or FALSE:
Atoms of different elements all have the same mass but differ in size and shape.
false
