Chemistry 1
A reaction that combines into a new substance is what kind of chemical reaction?
synthesis/combination reaction
the periodic table is organized by increasing _______, aka number of protons
atomic number
scientist who developed the Atomic Theory that we still use today
Dalton
the general rule that atoms prefer to have a full valence shell of 8 electrons
octet rule
elements that are brittle, not shiny, soft, and don’t conduct electricity.
nonmetals
As you go down a group, atomic radius ___?____ because there are more ___?____.
a) decreases; occupied energy levels
b) decreases; protons
c) increases; occupied energy levels
d) increases; protons
c. increases, occupied energy levels
covalent
each one can only hold 2 electrons, but there can be multiple in a sublevel
orbitals
What type of reaction is this:
A + B ----> AB
a) double replacement
b) decomposition
c) synthesis
d) single replacement
Synthesis.
Electrons located in the outermost energy level of an atom are called
valence electrons
molecules that share a negative or positive charge, like NH4+, are called ____?____ ions
polyatomic
boiling water, melting ice cream, and shredding paper are all examples of ____?____ changes.
physical
The effect of electrons repelling other electrons in the same atom and hiding valence electrons from the positive charge of the nucleus:
electron protection
electron shielding
nuclear protection
nuclear shielding
2. electron shielding
Ion
Mendeleev
The elements can be found in the far right group of the periodic table (group 18)
noble gases
On the periodic table, elements in _______ typically have similar chemical and physical properties.
a) trends
b) blocks
c) periods
d) groups
groups
What do enzymes do?
Speed a chemical reaction
Combustion reactions always produce all of these EXCEPT
Carbon dioxide
Water
Heat
Oxygen
4. oxygen
Elements represent unique forms of these little thingies. The building blocks of everything!
Atoms
When one chemical changes its state of matter, the change is called
What is Physical Change
What is the proper name for this formula: AlF3
Aluminum fluoride
Which type of solid has a "sea of electrons"?
Metallic
Name 4 types of chemical Reactions
Decomposition, synthesis, single replacement, double replacement, combustion
Double replacement reactions occur when the _____ or _____ ions of two ionic compounds exchange places to form two new compounds.
a) Polyatomic, molecular
b) Type I and Type II
c) Monatomic, diatomic
d) Positive, negative
d) positive and negative
Group 17 elements are called:
halogens
What is the proper formula for this compound: copper (II) iodide
CuI2
Which are definite signs of a chemical reaction taking place?
a. change of state
b. different color
c. precipitate formation
d. gas formation
e. change in volume
c. and d.
The s-sublevel has a ______ shape.
spherical
an element that can only conduct electricity at extremely high temperatures
semiconductors
What factors influence atomic radius size?
nuclear charge/number of protons and number of shells/distance between nucleus and valence electrons
Explain the difference between mass number and average atomic mass: 1 minute 30 seconds
mass number = individual atoms, sum of protons and neutrons
avg atomic mass = sum of all masses of different isotopes by abundance
Explain electronegativity, 1 minute
The ability of an atom to pull SHARED electrons closer towards itself.
What are 3 things a Lewis Diagram can show us that a regular molecular formula cannot? Think of a water molecule.
1. arrangement of atoms
2. types of bonds (single, double, triple)
3. valence electrons/lone pairs
4. molecular geometry/shape
Explain ionization energy: 1 minute
Energy required to remove an electron from the outermost shell of an atom. Increases as more electrons are taken.
Why are ionic solids brittle but metals are not?
ionic solids have a crystal lattice structure composed of positive and negative ions that, if shifted, can cause similar ions to interact and cause a repulsive reaction.
metals have a sea of free electrons that move around each cation so when force/stress is applied to the metal, the electrons are able to move between cations and prevent any repulsive forces from occurring.
Explain why fluorine has a smaller atomic radius than oxygen. 2 minutes
fluorine and oxygen have the same number of occupied energy levels/shells, however fluorine has a greater number of protons/stronger nuclear charge that pulls in the valence electrons more tightly compared to oxygen.