(Ch.5) Molecules & Compounds

Question 1

Describe the Law of Constant Composition.

Answer 1

Compounds display constant composition. This means any sample of a compound will have the same ratio of atoms within it.
(ex. H20= 8.0 grams of O:1.0 gram of H)

Question 2

What will be left if a compound decomposes?

Answer 2

Their original elements will remain.

Question 3

What is a Chemical Formula?

Answer 3

This is how we represent compounds. A ratio of atoms in a formula.
(ex. H2O)

Question 4

How do we decide what atom is listed first when writing compounds? There are two rules.

Answer 4

1. Metals are listed first.
2. The more metallic element is listed first.

Question 5

How do you determine which element is “more metallic?”

Answer 5

The element further to the bottom. (vertically)
The element further to the left. (horizontally)

Question 6

Describe a Empirical Formula.

Answer 6

This formula shows the simplest whole number ratio of atoms in a compound.
(ex. HO instead of H2O2, just a simplified ratio)

Question 6

What are the two primary types of Chemical Formulas?

Answer 6

1. Empirical Formulas
2. Molecular Formulas

Question 6

What is a Polyatomic Ion?

Answer 6

These are groups of atoms that act as a unit and have a charge. (Ion with more than one atom)

Question 7

Describe a Molecular Formula.

Answer 7

This formula shows the actual number of atoms of each element in a compound.
(ex. H2O2 instead of HO)
(This is a kind of Chemical Formula)

Question 8

What are the four primary models/formulas used to represent a molecule?

Answer 8

1. The Molecular Formula
2. The Structural Formula
3. The Ball & Stick Model
4. The Space-Filling Model.

Question 9

Describe the Structural Formula.

Answer 9

This model shows each atoms ARE connected to one another, along with how many of each they are.
H
H-C-H
H

Question 10

Describe the Ball and Stick Model.

Answer 10

This model helps us visualize the molecules SHAPE. The atoms are balls and the bonds are sticks.

Question 11

Describe the Space-Filling Model.

Answer 11

This is our best representation of how atoms actually look. Making molecules look like a bunch of large circles stuffed together.

Question 12

Elements have two subcategories. What are they?

Answer 12

1. Atomic Elements
2. Molecular Elements

Question 13

Compounds have two subcategories. What are they?

Answer 13

1. Ionic Compounds
2. Molecular Compounds

Question 14

What is a Molecular Compound? What is their base unit?

Answer 14

1. These are compounds composed of 2 or more NON-metals.
2. Molecules

Question 15

What is an Ionic Compound? What is their base unit?

Answer 15

1. These are compounds composed of a metal and a non-metal.
2. Formula Unit

Question 16

How do you differentiate between an Atomic and Molecular Element?

Answer 16

Atomic Elements have singular atoms as their base unit.
Molecular Elements are Diatomic- meaning they always naturally appear in pairs as their base unit.

Question 17

What is a Diatomic Molecule?

Answer 17

This is the base unit of a Molecular Element.

Question 18

There are seven naturally occurring Diatomic Molecules. What are they?

Answer 18

BO(o) FINCH
-Bromine
-Oxygen
-Fluorine
-Iodine
-Nitrogen
-Chlorine
-Hydrogen