Science Grade 4 Unit 02: Mixtures and Solutions

Transcription

1 Study uide and Science Investigation Questions Science rade 4 Unit 02: Mixtures and Solutions Please study the highlighted correct answer for each statement or question and complete each related inquiry for each statement or question.

2 1 How would a combination of pebbles and water be similar to a combination of sand and water? They are mixtures. They are solutions. Explain how you know they are mixtures. C D They are evenly dispersed. They dissolve in the water. 2 combination of substances has the following properties: blend of two or more substances evenly dispersed cannot be separated easily This combination of substances is known as a suspension solution H Write mixture the definition for solution. Solution: J solvent liquid mixture where one substance is mixed evenly throughout another substance. 3 old is a very soft metal that is used in jewelry. Since the metal is so soft, it is mixed with copper to give it more strength. To do this, both materials are melted into a liquid and mixed together to form a solution. When completely mixed together, it is cooled back down into a solid. Which of the following combinations is most like the material that makes up gold jewelry? salt water in sugar water iron filings in salt water How did you come to this conclusion? C beach sand in salt water D small pebbles in sugar water

3 4 The table shows different sizes of particles found in a sample of sand. Students have a strainer with holes that are 500 micrometers wide. The strainer could be used to separate which of the following mixtures? Very fine sand and fine sand ine sand and medium sand H Medium sand and coarse sand How J many Coarse micrometers sand and very did the coarse medium sand How many micrometers did the course sand sand have? have?

4 5 What does a mixture of rocks and water have in common with a mixture of salt and water? In both mixtures - C D two substances are combined a solid dissolves in a liquid the same substances are used the final appearance is the same 6 You are conducting a laboratory investigation on mixtures and solutions. Your lab materials include a balance, a beaker, a hot plate, water, vinegar, epsom salt, sugar, and an unknown substance. Proper safety when conducting an investigation should always be a priority. ll of the following are good safety practices EXCEPT review all safety rules before starting the investigation if a chemical spill occurs, clean it up first, and then report it to your teacher H wear protective equipment, such as safety goggles Name at least two good safety practices you should follow during an investigation. J make sure your equipment and lab area are clean before beginning the investigation

5 7 ll of the items below are mixtures. Which of the following is true of each mixture? C Each mixture is also a solution. Each mixture has a part that dissolves. Each mixture can be separated easily. How D can Each youmixture separate has each the same mixture physical easily? properties. 8 How is a bowl of salad without dressing and a bowl of hot soup different? The salad mixture is uniform, while the soup is non-uniform. Some of the material in the soup has dissolved, while nothing in the salad has dissolved. H The soup mixture is uniform, while the salad is non-uniform. Why didn't the salad dissolve? J The salad mixture is made from two states of matter, while the soup is only one state of Why did matter. some of the material in the soup dissolve?

6 9 combination of substances has the following properties: blend of two or more substances same properties as their components can be separated This combination of substances is known as a suspension solution C mixture D List solvent substances that could possibly be in this mixture. 10 magnet would be most useful in separating which of the following mixtures? H J Salt and water Rocks and soil Sugar and iced tea Iron filings and sand Explain why a magnet would be most useful in separating iron filings and sand.

7 11 student stirred 10 grams of salt into 50 ml of water and 10 grams of sand into 50 ml of water and let both mixtures sit for ten minutes. What important difference is observed between these two mixtures? C The salt, sand, and water do not mix together. Salt dissolves in the water but sand does not. Mixture 2 can be separated, but Mixture 1 cannot. Why D Mixture does the1 is salt a solid dissolve and ina liquid, the water but but Mixture not the 2 is sand? not.

8 12 student investigated what happens when different substances are added to water. The table shows his results. Substance Pepper Sand Sugar lour Result loats on the water Sinks to the bottom Seems to disappear orms a thick paste In which mixture does one substance dissolve in another? H Pepper and water Sand and water Sugar and water Does J Sugar dissolve in water? Does sugar dissolve in hot tea? Why? E SURE YOU HVE RECORDED LL O YOUR NSWERS ON YOUR NSWER DOCUMENT STOP