Unit 2 Study Guide Flashcards
(42 cards)
What are the three main subatomic particles?
Protons, neutrons, and electrons
What is the nucleus of the atom composed of?
Protons and neutrons
What is the relative size of the nucleus to the rest of the atom?
Really, really small (marble to football stadium/ 1 x 10^15)
What are the relative weights and charges of a proton, neutron, and electron?
Proton- +1; 1.007
Neutron- 0; 1.008
Electrons- -1; 5.45 x 10^-4
(numbers aren’t important, just know electrons are puny and protons and electrons are about the same size)
What does the atomic number of an atom represent?
Number of protons
What does the atomic mass of represent?
Number of protons plus the number of neutrons
How can you find the number of electrons a neutral atom has?
The number of protons equals the number of elcetrons
What is an isotope?
An atom with a different number of protons and neutrons
What is the difference between a stable isotope and and unstable one?
Unstable isotopes (radioisotopes) decay while stable ones do not
How is the stability of an isotope defined?
The stability of an isotope is defined by whether or not the isotope undergoes radioactive decay
What happens to an unstable isotope?
Unstable isotopes undergo radioactibve decay
What is an alpha particle?
An alpha particle is an atom with 2 protons and 2 neutrons (Helium-4)
Differentiate fusion and fission.
Fusion- nuclei combine to form a greater mass
Fission- splitting of nuclei into smaller fragments
Show the different ways to represent elements with their masses.
Ex: Uranium-238; 4/2 He
Differentiate between the average atomic mass and the mass number of an element.
Avg. atomic mass: average combined number of protons and neutrons in a given element
Mass number: number of protons and neutrons in a given atom
What is a horizontal row of the periodic table called?
Period
In what order are the elements listed on the periodic table?
The elements are listed by atomic number
What is a group on the periodic table?
Family/ column of elements
What is an ion?
An atom with a different number of protons and neutrons
Differentiate between a cation and anion?
Cations- atoms with positive charges
Anions- atoms with negative charges
Where are the cations located on the periodic table?
Left of the carbon group
Where are the anions located on the periodic table?
Right of the carbon group
How do the number of valence electrons relate to an element becoming an anion or cation?
Cation- element has less than 4 valence electrons
Anion- element has more than 4 valence electrons
What is a valence electron?
An electron on the highest occupied energy level of an atom
