Module 4 Flashcards
(15 cards)
What are valence electrons and why are they important?
they are the electrons that are farthest away from the nucleus. They are important because they are responsible for determining the chemical behavior of an atom.
How many valence electrons are I the following electron configuration?
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p3
5 valence electrons
The chemistry of life is based on carbon. This means that all of the molecules which govern life-giving chemistry have carbon atoms as their principal component. Chemists have often speculated that there could be a life form with a chemistry based on silicon. Why?
in theory, life could be based on any atom in the same column as carbon (like silicon). (all compounds in 4A have 4 valence electrons which makes them ideal central atoms)
What are the noble gases and why are they important in chemistry?
they are elements in group 8A. They are important because the have ideal electron configurations.
What is the octet rule? Give 2 exceptions to this rule.
Most atoms strive for 8 valence electrons. Hydrogen, helium, lithium, boron, and beryllium are exceptions.
What is the fundamental difference between metals and nonmetals?
Metals tend to give up electrons to attain the ideal electron configuration. nonmetals tend to gain electrons for the same purpose.
Critique this statement: The number at the top of a columns on the periodic table is the number of valence electrons that all elements have.
this statement only applies to the columns of the periodic table labeled with the letter A. (B columns have 2 valence electrons).
What is the difference between and atom and an ion?
An Atom has an equal number of protons and electrons no electrical charge. Ions have electrical charge because they have and imbalance of protons and electrons.
What is ionization energy?
it is the amount of energy needed to take an electron away from an atom
Name 3 periodic properties of atoms.
Ionization energy, electronegativity, and atomic radius
Describe how the periodic properties vary as you move up a column and to the right along a row of the periodic table.
Ionization energy and electronegativity increase as you move up a column and to the right along a row of the periodic table.
Atomic Radius decreases as you move up a column and to the right along a row of the periodic table.
What is the fundamental difference between ionic compounds and covalent compounds?
Ionic compounds form when atoms give and take electrons, thus they are composed of ions. covalent compounds result when atoms share electrons. Thus, no ions are formed.
What is wrong with the following formula: Mg2O2?
ionic formulas need to be in the lowest possible ratio. MgO
What gases are involved in earth’s 3-tierd protection system against high-energy light that comes from the sun.
Nitrogen, Oxygen, and ozone
List the homonuclear diatomics.
N2, O2, Br2, Cl2, F2, I2, At2, H2
