Layered liquids in a cylinder showing varying densities with colorful layers.

Problem Analysis:

The image shows a layered liquid column with different substances. The task is to explain why these liquids form distinct layers and how their arrangement is determined.

Key Concepts:

1. Density: Liquids with different densities will separate into layers, with the denser liquid settling at the bottom and less dense liquids floating on top.
2. Solubility: Substances that are immiscible (do not mix) will form distinct layers based on their density.
3. Viscosity: While viscosity affects flow, it does not directly determine layering in this context; density is the primary factor.

Step-by-Step Explanation:

#### 1. Dark Corn Syrup (Bottom Layer)
- Density: Dark corn syrup is very dense due to its high sugar content.
- Behavior: It settles at the bottom of the column because it is the densest liquid among the given substances.

#### 2. Dishwashing Liquid
- Density: Dishwashing liquid is less dense than dark corn syrup but more dense than water.
- Behavior: It forms a layer above the dark corn syrup because it is less dense than syrup but heavier than water.

#### 3. Colored Water
- Density: Water has a moderate density compared to the other substances.
- Behavior: It floats above the dishwashing liquid because it is less dense than dishwashing liquid but denser than oil-based substances.

#### 4. Corn Oil
- Density: Corn oil is less dense than water.
- Behavior: It forms a layer above the colored water because it is immiscible with water and less dense.

#### 5. Colored 70% Isopropanol
- Density: Isopropanol ( rubbing alcohol) is less dense than water but more dense than mineral oil.
- Behavior: It forms a layer above the corn oil because it is denser than oil but less dense than water.

#### 6. Mineral Oil
- Density: Mineral oil is less dense than isopropanol.
- Behavior: It forms a layer above the isopropanol because it is immiscible with isopropanol and less dense.

#### 7. Colored 90% Ethanol
- Density: Ethanol is less dense than water but more dense than mineral oil.
- Behavior: It forms the topmost layer because it is the least dense among the remaining substances.

Final Arrangement:

The liquids are arranged in order of decreasing density from bottom to top:
1. Dark corn syrup (densest)
2. Dishwashing liquid
3. Colored water
4. Corn oil
5. Colored 70% isopropanol
6. Mineral oil
7. Colored 90% ethanol (least dense)

Conclusion:

The layering is determined by the relative densities of the liquids. Denser liquids settle at the bottom, while less dense liquids float on top. Immiscibility ensures that the layers remain distinct.

Final Answer:

\[
\boxed{\text{The liquids are layered based on their densities, with the densest at the bottom and the least dense at the top.}}
\]