Unit 1
Atomic structure/
Periodic Trends
Atomic structure/
Periodic Trends
What is an atom?
What is a molecule?
An atom is the smallest unit of an element that retains the properties of the element. Or an element is the "building blocks of matter."
A molecule is a combination of atoms that are chemically combined.
What is a Valence electron?
These electrons are a primary focus in Chemistry, why?
An electron on the outer shell of an atom.
These are the electrons that interact with other atoms to chemically bond.
What is a mole?
There are 3 right answers, each worth 100 points.
A mole is:
A specific number (like a dozen (12), or a score (20).
6.022x10^23 particles
The conversion factor from A.M.U. to grams
What are the terms for the chemicals on the Left and the Right side of a chemical reaction?
The chemicals on the left side of a chemical reaction are known as the reactants.
The chemicals on the right side of a chemical reaction are known as the products.
In the reaction:
Mg + S -> MgS
If you have 3 atoms of Mg and 3 atoms of S, how many molecules of MgS are produced?
3 molecules of MgS
Label the following compounds as either Ionic or Covalent.
K2O Mg3N2 CaCl2
They're all Ionic, because they are all composed of 1 metal, and 1 nonmetal.
What is the Molar Mass of CO2? (Pull all values rounded to the 3rd digit.) INCLUDE UNITS
44 Grams/Mole
meaning there are 44 grams of CO2 in 1 mole of CO2
Or that it take 6.626x10^23 molecules of CO2 to weight 44 grams
Name the 5 main types of Chemical reactions
Synthesis
Decomposition
Combustion
Single Replacement/Single Displacement
Double Replacement/Double Displacement
In the reaction:
Mg + S -> MgS
If you have 5 moles of Mg and 5 moles of S, how many moles of MgS are produced?
5 moles of MgS
Since a mole is just a number of atoms/molecules, we use the same reasoning as the last question, the method doesn't change as the numbers get larger.
How many Protons, Electrons, and Neutrons does an atom of sulfur with a mass of 35 amu and a charge of +1 have?
16 Protons - SULFUR is the 16th element
15 Electrons - POSITIVE 1 means that there is 1 more proton than electron, since there are 16 Protons, there are 15 electrons
19 Neutrons - MASS - #protons = #neutrons
In an ionic compound like Lithium Phosphide (Li3P), how do we know there are 3 Lithium atoms and 1 Phosphorous atom?
In a Covalent compound like Carbon Dioxide (CO2) How do we know there is 1 Carbon atom and 2 Oxygen atoms?
For an IONIC Compound you have to balance the IONIC charges of the 2 elements.
For a Covalent Compound, you check for prefixes on the elements to determine the number .
(remember that the only time an element doesn't need a prefix is if it is listed first and there is only 1 atom_
How many moles of Carbon do you have if you have 66 grams of Carbon? INCLUDE UNITS
5.5 moles
The Law of Conservation of Mass states that matter is neither created nor destroyed during a chemical reaction.
In the reaction:
2H2 + O2 -> 2H2O
If you have 3 moles of the molecule H2 How many moles of H2O will be produced? How many moles of the molecule O2 will be used?
The reaction will use 1.5 moles of O2 to produce 3 moles of H2O
What is ATOMIC RADIUS?
Describe the trend of ATOMIC RADIUS for elements as we go across the Periodic table from Left to Right, and as we go down the table from top to bottom
Atomic Radius describes the size of an atom, it is the distance from the center of the nucleus to the outside edge of it's largest filled orbital.
From Left to Right A.R. decreases
From Top to Bottom A.R. increases
Draw me a Lewis Dot Structure for the covalent compound phosphorous trifluoride PF3
To be drawn on the whiteboard
If you have 80.5 Liters of a gas at STP how many moles of the gas do you have?
(Recall that 1 mol of a gas occupies a volume of 22.4L at STP)
Must show work and include units in your answer.
3.59 moles
In the following reaction, If you have only 4.04 grams of Hydrogen, and you want to produce 36.04 grams of H2O what is the minimum amount of Oxygen you need
2H2 + O2 -> 2H2O
At least 32 grams of Oxygen are required.
If you have more than 32 grams, what happens to the rest of the Oxygen?
If you run the imaginary reaction:
7N2 + 3O2 -> N14O6
and you have 14 moles of Nitrogen and 9 moles of Oxygen, which gas will you run out of first?
You will run out of Nitrogen first, the reaction uses 7 moles of Nitrogen and 3 moles of Oxygen,
14/7 = 2 and 9/3 = 3
So (in an ideal scenario) the reaction will run until it produces 2 moles of N14O6
What is ELECTRONEGATIVITY?
Describe the trend of ELECTRONEGATIVITY for elements as we go across the Periodic table from Left to Right, and as we go down the table from top to bottom
Electronegativity describes how strongly an atom attracts electrons outside of it's electron cloud.
As we go from Left to Right Electronegativity increases
As we go from Top to Bottom Electronegativity decreases
Draw me a Lewis Dot Structure for the Ionic Compound Potassium Nitride K3N
To be drawn on the Whiteboard
If you have 7.80x10^40 molecules of H2O how many grams of H2O do you have?
2.33x10^18 grams of H2O
Balance the reaction between Aluminum metal and Hydrochloric Acid (Also Called Hydrogen Chloride)
2Al + 6HCl = 2AlCl3 + 3H2
In the synthesis reaction:
2Li + S -> Li2S
If you have an excess of Lithium and use 96.3 grams of Sulfur how much Lithium Sulfide is produced?
110.18 grams