Chemistry Atomic models
Atomic mass is a ---
Weighed average of all the naturally occurring isotopes
The table below gives the masses of two different subatomic particles found in an atom. Subatomic Particle. Mass(g) X. 1.67 X 10-24 Z. 9.11 X 10-28 Which of the subatomic particles are each paired with their corresponding name?
X, proton and Z, electron
Rutherford concluded that the atom was mostly empty space with a -------
positively charged volume smaller than the atom
The table below shows the atomic mass and natural abundance of the two naturally occurring isotopes of lithium. Which numerical setup can be used to determine the atomic mass of naturally occurring lithium?
(.076)(6.015u)+(.924)(7.016u)
Some information about the two naturally occurring isotopes of gallium is given in the table below. Which numerical setup can be used to calculate the atomic mass of gallium?
(.6011)(68.926u)+(.3989)(70.925u)
What is the approximate mass of a proton?
1 u
Which notations represent hydrogen isotopes?
1/1 H and 2/1 H
An atom that contains six protons, six neutrons, and six electrons has a mass of approximately
12 u
What is the overall charge of an ion that has 12 protons, 10 electrons, and 14 neutrons
2+
What is the number of electrons in an atom that has 3 protons and 4 neutrons
3
What is the number of electrons in a completely filled second shell of an atom?
8
Which particles have approximately the same mass?
A neutron and a proton
Which statement describes the distribution of charge in an atom
A positively charged nucleus is surrounded by one or more negatively charged electrons
Which particle has the least mass?
An electron
Which statement describes the charge of an electron and the charge of a proton?
An electron has a charge of -1 and a proton has a charge of +1
What is matter?
Anything that has mass and volume
Isotope is an -----
Atom that has the same proton number but different atomic masses, the number of neutrons change
On the Periodic Table, the number of protons in an atom of an electron is indicated by its
Atomic number
What was JJ Thomson's Model?
Cathode ray tube
Valance electrons determine -- and ---
Chemical properties and participate in binding
As a result of the gold foil experiment, it was concluded that an atom
Contains a small, dense nucleus
What did JJ Thomson call the negatively charged particles?
Corpuscles
Each diagram below represents the nucleus of a different atom. Which diagram represents nuclei of the same element?
D, E, and Q
Four statements about the development of the atomic model are shown below A: Electrons have wavelike properties B: Atoms have small, negatively charged particles C: The center of an atom is a small, dense nucleus D: Atoms are hard, invisible spheres Which order of statements represented the historical development of the atomic model?
D,B,C,A
Who was the first one to come up with atomic theory?
Dalton
Location and charge of an electron
Electron cloud -1
Bohr's model considered concentric circular orbits of -
Electrons
The proton and the electron both have a ----
Magnitude of 1 however the charges are opposite
What is the average atomic mass formula?
Mass isotope 1 (% isotope 1/100)+mass isotope 2 (%isotope2/100)
The electrons further away from the nucleus have --
More energy
The table below indicated the stability of six nuclides. All atoms of the unstable nuclides listed in this table have
More neutrons than protons
Rutherford concluded that an atom is composed of -----
Mostly empty space with a small, dense, positively charge nucleus
A (atomic mass) contains the number of - and -
Neutrons and protons
The stability of isotopes is related to the ratio of which particles in the atoms?
Neutrons and protons
Rutherford also called this positively charged volume the -
Nucleus
Location and charge of a proton
Nucleus +1
Location and charge of a neutron
Nucleus -
In the wave mechanical model, electrons are in -----
Orbitals which are the most probable location of election
The gold foil experiment led to the conclusion that each atom in the foil was composed mostly of empty space because most alpha particles directed at the foil
Passed through in the foil
Z (atomic number) is the number of
Protons
Atoms have the same number of - and -
Protons and electrons
What was Dalton's model?
The Solid Sphere model
What is volume?
The amount of space a 3- dimensional object takes up
The diagram below represent the nucleus of an atom. What are the atomic number and mass of this atom?
The atomic number is 9 and the mass number is 20.
Compared to the charge of a proton, the charge of an electron has
The same magnitude and the opposite sign
The total number of protons, electrons, and neutrons in each of four different atoms are shown in the table below. Which 2 atoms are isotopes of the same element?
A and D
Opposite forces -
Attract
Who proposed the model of a hydrogen atom?
Bohr
Who called the invisible units atomos (atom)?
Democritus
Name the models in order
Democritus Dalton JJ Thomson Rutherford Bohr Wave mechanical model
In the late 1800s, experiments using cathode ray tubes led to the discovery of the
Electron
Elections are diffuse and spread out in a negatively charged cloud called the --
Electron cloud
What was Democritus theory?
If one were to cut in half continuously, eventually one would arrive at an indivisible unit of the object
What was JJ Thomson's atomic model also called?
Plum pudding model
Like forces -
Repel
Who conducted the gold foil experiment
Rutherford
What is mass?
The measure of a number of atoms in a particular substance
The atomic mass of an element is the weighed average of the atomic masses of
The naturally occurring isotopes of the element
Electrons in the outer most shell are called --
Valance electrons
