1) This document discusses scientific investigations including descriptive, classificatory, and experimental investigations. It focuses on experimental investigations and the key components of experiments such as developing hypotheses, identifying variables, collecting data, and drawing conclusions. 2) As an example, it describes an investigation using M&Ms placed in water to observe how color and other variables affect dissolution. It identifies questions that could be investigated and variables that could be manipulated or controlled. 3) It explains how water is able to dissolve many substances like sugar due to water's polar nature and how water and sugar molecules interact through attraction of opposite charges.

1. SCED 475, Fall 2009 by Dr. Song Chapter 2: SCIENTIFIC INVESTIGAIONS

2. WILL IT FLOAT OR SINK?

3. 1. descriptive Investigation : gather observational and measurement data to answer questions about the properties and actions of objects, organisms, events, and systems 2. Classificatory Investigation : organize collected information by sorting and grouping it according to one or more properties in order to identify relationships and better define properties

14. Law of inertia: A body in motion will continue in motion, unless acted upon by a force

16. Investigations M & M

19. Color of the M & M’s

20. The number of M & M’s

21. The temperature of water

22. Type of liquid & the concentration of the solution in which the M & M’s are placed

23. Questions you could investigate

24. Do some M & M colors dissolve in water faster than others?

25. What would the colors look like if we place two or more M & M’s in a plate of water?

26. Does the temperature of the water affect how fast the colored coating dissolves from an M & M?

28. What happened? & Why? Sugar (sucrose) also has oxygens and hydrogens bonded to each other. This gives sucrose many areas of positive and negative charge.

29. What happened? & Why? Water and sucrose are attracted to one another based on the attractions of opposite charges. When the attraction that water molecules have for sucrose overcomes the attraction sucrose molecules have for each other, the sucrose dissolves. The polar nature of water is what makes water so good at dissolving many substances.

30. HOW SMALL? The drawings and models of water molecules that you see or build are millions of times larger than the actual size of real water molecules. To get an idea of how small they are, consider this: Let’s say you had about a tablespoon of water and wanted to count all the water molecules in that amount of water. Assume you were a very fast counter and could count 1 million water molecules every second. Even at your very fast counting speed, it would take you over 190 million centuries to count all the water molecules in that small amount of water. WOW!