Physical Science Exam: Chapter 4
Who provided evidence for the existence of a nucleus in an atom?
Ernest Rutherford
All isotopes of the same element have the same mass number
False
All subatomic particles have the same mass
False
An isotope is an atom that has lost protons
False
In an atom the atomic number, the number of protons and the number of neutrons are always the same
False
James Chadwick discovered electrons
False
Most of the mass of an atom is located in the electron cloud
False
Protons and electrons are located in the nucleus
False
A proton has a mass of 1 AMU
True
An atom of one element is different from an atom of another element because of its atomic number
True
An ion is an atom that has gained or lost an electron
True
If an ion has lost electron its charge will be positive
True
The overall charge of an atom is neutral, because it has the same number of electrons and protons
True
Which of the following is NOT part of John Dalton's atomic theory? a. Atoms contain subatomic particles b. All elements are composed of atoms c. A compound contains atoms of more than one element d. All atoms of the same element have the same mass
a. Atoms contain subatomic particles
Which statement about subatomic particles is NOT true? a. Protons and neutrons have the same charge b. Protons and neutrons have almost the same mass c. Protons and electrons have opposite charges. d. Unlike protons and electrons, neutrons have no charge
a. Protons and neutrons have the same charge
Which of the following is unique for any given element? a. the number of protons b. the mass of a neutron c. the charge on the electrons d. the number of neutrons
a. the number of protons
The Greek philosopher Democritus coined what word for a tiny piece of matter that cannot be divided?
atom
The number of protons in one atom of an element is that element's
atomic number
To find the number of neutrons in an atom, you would subtract
atomic number from mass number
Which statement about subatomic particles is true? a. Neutrons have no charge and no mass b. Protons, neutrons, and electrons all have about the same mass c. An electron has far less mass than either a proton or neutron d. Unlike protons or neutrons, electrons have no mass.
c. An electron has far less mass than either a proton or neutron
Rutherford's gold foil experiment provided evidence for which of the following statements? a. Alpha particles have a positive charge b. Negative and positive charges are spread evenly throughout an atom c. There is a dense, positively charged mass in the center of an atom d. Gold is not as dense as previously thought
c. There is a dense, positively charged mass in the center of an atom
Which statement is true about oxygen-17 and oxygen-18? a. Their atoms have an identical mass b. The have the same mass number c. They are isotopes of oxygen d. They do not have the same number of protons
c. They are isotopes of oxygen
J. J. Thomson's experiments provided evidence that an atom
contains negatively charged particles
Which of the following most accurately represents John Dalton's model of the atom? a. a hollow sphere with a dense nucleus b. a tiny, solid sphere with an unpredictable mass for a given element c. a sphere that is hollow throughout d. a tiny, solid sphere with a predictable mass for a given element
d. a tiny, solid sphere with a predictable mass for a given element
Which subatomic particle has a negative charge?
electron
In Niels Bohr's model of the atom, electrons move
like planets orbiting the sun
Democritus thought that matter was made of tiny particles
that could not be divided
What does the electron cloud model describe?
the most likely locations of electrons in atoms
According to John Dalton's observations, when elements combine in a compound,
the ratio of their masses is always the same