Chapter 4 Test Flashcards
Which Greek philosopher proposed the idea that matter is made of tiny individual particles called atoms?
Democritus
In Ancient it was proposed that matter is composed of earth, air, fire and water and that these elements are in what?
Continual Motion
which of the following elements is part of the Dalton’s Atomic Theory?
Different elements combine in a simple whole number ratios to form compounds
In the early 1900’s it was proposed that energy may be absorbed or released from small atoms, indivisible packets names?
Quanta
The development of the cathode ray tube let to the discovery of what subatomic particle?
Electron
Electrons have the properties of?
Particles and Waves
Experimental Evidence indicates that the nucleus of an atom
Contains most of the mass of the atom
In an experiment alpha particles were used to bombard gold foil. As a result of this experiment, the conclusion was made that the nucleus of an atom is…
smaller than the atom and positively chaged
After bombing the gold foil with alpha particles the scientists concluded that the atom consisted of mainly
Empty Space
When alpha particles are used to bombard gold foil, most of the alpha particles pass through undeflected. This result indicates that most of the volume of a gold atom consists of
Unoccupied space
Compared to the entire atom, the nucleus of the atom is
Smaller and contains most of the atoms mass
What model of the atom proposes that electrons are located in the orbitals?
Wave Mechanical Model
What term refers to the region of atom where electron is most likely to be found?
Orbital
A region of most probable electron location in an atom called
Orbital
Which symbol represents a proton?
1 over 1 (positive)
Which Particle has the least mass?
An electron
What particle has a negative charge and a mass that is approximately 1/1836 the mass of a proton
An electron
The mass of an electron is approximately 1/1836 times the mass of what?
A proton
What is the approximate mass of an electron?
1/1836 of a proton
What statement best describes and electron?
Similar mass than a proton and negative charge
What particle has the mass of approximately one atomic mass unit and a unit positively charged?
A proton
What particle is electrically neutral?
Neutron
What particle has approximately the same mass as a proton?
Neutron
Which two particles have approximately the same mass?
Proton and Neutron
What two particles account for most of the mass in an atom?
Proton and Neutron
What are the nucleons in an atom?
Protons and Neutrons
How many protons are in the nucleus of an atom of beryllium?
4
What kind of particle when passed through an electric field, would be attracted to the negative electrode?
An alpha particle
A particle has a mass of 1.0 atomic mass unit. What is the approximate mass of this particle in grams?
1.7x(10)^-24
What kind of radiation will travel through an electric field, on a pathway that remains unaffected by the field
A gamma ray
What particle will be attracted to the positive electrode in an electric field?
A beta particle
What particle has a negative charge?
A beta particle
All atoms of an element have the same what?
Atomic Number
All atoms in a given sample of an element contain the same number of what?
Protons and Neutrons
The atoms in a sample of an element must contain nuclei with the same number of…?
Protons
The atomic number of an atom is always equal to the total number of
protons in the nucleus
Two atoms will always have the same atomic number if they have the same
Number of protons
In a sample of pure copper all atoms have
The same atomic number and the same number of protons
A substance that is composed only of atoms that have the same atomic number is classified as
An element
Which substance is composed of atoms that all have the same atomic number?
Magnesium
All of the atoms of argon have the same…
Atomic Number
As the number of neutrons in the nucleus of an atom increases the nuclear charge does what?
Stays the same
What is the nuclear charge of an atom with a mass of 23 and an atomic number of 11
11+
As an Na atom forms an Na+ ion, the atomic number of protons in its nucleus
Remains the same
A sodium atom and a sodium ion must have the same number of
protons
The total number of protons found in an OH- ion is
9
Which atom contains exactly 15 protons
Phosphorus-32
What were the four points to Daltons Atomic Theory?
All elements are composed of tiny indivisible particles
Atoms of the same element are identical. The atom of any one element are different from those of any other element
Atoms of different elements can physically mix together or can chemically combine into a simple whole number ratio to form compounds
Chemical Reactions occur when atoms are separated from each other joined or rearranged in a different combination. Atoms of one element however are never changed into atoms of another element due to chemical reaction
Who discovered the Neutron?
James Chadwick
