Journal of Baltic Science Education,
By Kose, Sacit
“The effect of concept mapping instructions overcoming 9th grade students’ misconceptions”
Publisher: 1648–3898
2/6
2007
The effect of concept mapping instructions overcoming 9th grade students’ misconceptions
Type: Empirical
Data collection method: Conceptual inventory
Number of subjects, range: Small — 10 or fewer
Grade and age of subjects: 9th-12 grade — 15-18 years
Process of diffusion
- The process responsible for a drop of blue dye becoming evenly distributed throughout a container of clear water is:
- diffusion because the dye separates into small particles and mixes with water.
- osmosis because there is movement of particles between regions of different concentrations.
2. When sugar is added to water, after a very long period of time the sugar will be more concentrated on the bottom of the container because:
- there will be more time for settling.
- the sugar is heavier than water and will sink.
- sugar dissolves poorly or not at all in water.
Process of osmosis
- Two columns of water are separated by a membrane through which only water can pass. Side 1 contains dye and water; side 2 contains pure water. After 2 hours, the water level in the side 1 will be higher because water will move from the hypertonic to the hypotonic solution.
- will be higher because water moves from low to high concentrations..
- will be lower because water will move from the hypertonic to the hypotonic solution.
- will be the same because water will become isotonic.
2. If a freshwater plant cell were placed in a beaker of 25% saltwater solution, the central vacuole would:
decrease in size because salt absorbs the water from the central vacuole.
The particulate and random nature of matter
- Particulates move from high to low concentration because:
- they tend to move until the two areas are isotonic and then the particles stop moving.
- there are too many particles crowded into one area, therefore they move to an area with more room
2. As the difference in concentration between two areas increases, the rate of diffusion:
- increases because the molecules want to spread out.
- decreases because if the concentration is high enough, the particles will spread less and the rate will be slowed.
3. When a drop of dye is placed in a container of clear water the:
- dye molecules continue to move around because if dye molecules stopped, they would settle to the bottom of the container.
- dye molecules continue to move around because this is a liquid; if it were solid the molecules would stop moving.
Influence of biological forces on diffusion and osmosis
- If a plant cell is killed and placed in a salt solution :
- diffusion and osmosis will occur because the cell will stop functioning.
- only diffusion will continue because osmosis is not random, whereas diffusion is a random process.
Concentration and tonicity
- A glucose solution can be made more concentrated by:
- adding more glucose because the more water there is, the more glucose it will take to saturate the solution.
- adding more waterSide 1 is hypotonic to side 2 because water moves from high to low concentration.
- Side 1 is hypertonic to side 2 because water moves from high to low concentration.
Membranes
- All cell membranes are:
- semipermeable because they allow some substance to enter, but they prevent any substance from leaving.
Kinetic energy of matter
1.Suppose there are two large beakers with equal amounts of clear water at two different temperatures (Beaker 1: 25°C, Beaker 2: 35°C). Next, a drop of green dye is added to each beaker of water. Eventually the water turns light green. Which beaker became light green first?
- Beaker 1 because the lower temperature breaks down the dye.
- Beaker 2 because it helps the molecules to expand.