Energy
The lowest energy state of a particle
What is ground state?
A substance that cannot be chemically broken down into simpler substances.
What is an element?
How many significant figures are in the following:
a. 106 mL
b. 1.20 x 103 cm
c. 0.0067000 in
a. 3
b. 3
c. 5
Define a physical change and give 3 examples that we often see in chemistry.
A physical change is a change in the state of matter that DOES NOT involve a change in the atoms or molecules present.
EX: dissolving, distillation, evaporation, melting, freezing, vaporizing, sublimation, condensation
What is the chemical formula of lithium oxide?
What kind of compound is this?
Li2O
Ionic
A chemist is studying the differences between red light and green light.
Which light has a higher frequency?
Which light has more energy?
Which light has a longer wavelength?
High Frequency - Green
High Energy - Green
Long Wavelength - Red
f = E/h
^ = c/f
(^ = wavelength)
How many protons, neutrons, and electrons are in the most abundant isotope of Carbon?
How many protons, neutrons, and electrons are in an atom of C-13?
6 protons, 6 electrons, 6 neutrons
6 protons, 6 electrons, 7 neutrons
A measure of how tightly-packed the matter in a substance is
What is density?
What type of reaction is the following:
8H2SO4 --> 8H2 + S8 + 16O2
Decomposition
Name 3 elements that behave similarly to Magnesium (Mg)
Beryllium, Calcium, Strontium, Barium, Radium
DAILY DOUBLE!!!
What is the frequency of green light, which has a wavelength of 511 nm?
5.87 x 1014 Hz
This property increases as you move up and to the right on the periodic table.
What is the periodic trend for electronegativity?
Silicon has a density of 2.3 g/mL. What is the volume of a silicon block that has a mass of 1.72 kg?
750 mL
Write the balanced equation for the formation of CH4O, and state the definition of this type of reaction and another name for a formation reaction.
2C + 4H2 + O2 --> 2CH4O
Synthesis is another name for a formation reaction; a reaction which starts with pure elements and ends with a compound.
What is the chemical name and formula of the compound formed by potassium and nitrogen?
K3N
Potassium Nitride (ionic)
What is the wavelength and energy of a photon with a frequency of 6.57 x 1022 Hz?
E = 4.36 x 10-11 J
wavelength = 4.57 x 10-6 nm
(1 nm = 10-9 m)
What is the full ground-state electron configuration for Iodine (I)?
1s22s22p63s23p64s23d104p65s24d105p5
Classify the following as an element, compound, heterogeneous mixture, or homogeneous mixture:
a. A sample of lithium chloride
b. A chocolate chip cookie
c. A silver wire
a. Compound
b. Heterogeneous Mixture
c. Element
Write and balance a chemical equation for the complete combustion of C2H6O.
C2H6O + 3 O2 --> 2CO2 + 3H2O
Give a clear definition of a HOMONUCLEAR DIATOMIC element AND name the 7 homonuclear diatomics.
A homonuclear diatomic element is one that exists as a pure element paired up with another atom of the same element in nature, UNLESS it is bonded with a different element to form a compound.
H, N, O, F, Cl, Br, I
Order the following in order of increasing energy. Then order them in order of increasing wavelength:
X-Rays, Visible Light, Microwaves
What is Energy:
Microwaves, Visible Light, X-Rays (highest E)
Wavelength:
X-Rays, Visible Light, Microwaves (longest)
Draw the Lewis structure, name the shape, and determine if the following compound is polar or not.
CH2O
Trigonal planar, Polar
A 101.96 g sample of a solid is broken down into 53.96 g of aluminum and an unknown amount of oxygen. If a chemist wants to make 1,937 g of that solid without any leftovers, how much aluminum and oxygen should she react together?
What scientific law helped you solve this problem?
101.96g S --> 53.96g Al + ____ g O
101.96 - 53.96 = 48.00g O
1937/101.96 = 19.00
Al: 53.96g * 19.00 = 1,025g Al
O: 48.00g * 19.00 = 912.0g O
Law of Conservation of Mass
DAILY DOUBLE!!
1) Write a balanced chemical equation for the double replacement reaction between lead (II) nitrate and potassium iodide, including symbols of state and coefficients. (Hint: nitrate is NO3 -1)
2) Describe the general format for a double replacement reaction, including how to know if a reaction actually takes place.
1) Pb(NO3)2 (aq) + 2 KI (aq) --> 2 KNO3 (aq) + PbI2 (s)
2) In a double replacement reaction, two aqueous solutions of ionic compounds are combined. They may or may not react. A reaction has occurred IF a solid is formed that is not dissolved, or a gas bubbles out of solution, or water is formed.
Give the SPECIFIC names for the compounds:
FeO
P2O5
Iron (II) oxide
Diphosphorus pentoxide