States of Water
Physical Change
Chemical Change
Physical vs. Chemical Change
100
One cold winter morning, you make three snowballs to throw at your older sister when she gets home from school later that day. That afternoon, when you look for the snowballs you made, they are gone. The most likely explanation for this is that
The snowball melted
100
A student folds a piece of paper into an origami shape, as shown here. Which of these statements justifies that this is a physical change that occurred?
The paper can be unfolded and will remain the same size.
100
When mixing 2 or more substances together, evidence that a chemical change occurred would NOT include
Responses
- A producing a gas.
- B change in color.
- C change in state of matter.
- D change in temperature.
C. change in state of matter
100
To make a cake, you combine flour, yeast, sugar and eggs. After mixing the ingredients, you place them in a pan in the oven to cook.
The breaking and then the mixing up of the eggs is
A Physical Change
200
To change liquid water into ice cubes you MUST
Decrease the temperature
200
IRON
Iron is the most common element forming the planet Earth and can be found in Earth's outer and inner core. It is the fourth most common element in the Earth's crust as well. Fresh iron surfaces appear silver-gray, but rusts easily in normal air. It is a solid at room temperature, but it is a soft metal. It is malleable and used for many tools and utensils. Iron is attracted to a magnet and can be magnetized. The melting point of iron is 2800oF.
Iron filings were mixed together with salt crystals. What unique property of iron would be BEST to separate the filings from the salt?
Magnetism
200
Which of the following can be considered a clue that a chemical change has occurred?
Responses
- A Size
- B Mass
- C Volume
- D Smell
Smell
200
Matter can change: the changes can be physical or chemical. When a physical change happens, nothing new is formed. During a physical change, matter changes form; it can be crushed or torn. It can also change state; for example, it can change from a solid to a liquid as it melts. When a chemical change occurs, something new is formed. The reactant or reactants change and become something new. For example, a piece of iron can rust. The rust is the new substance that is formed. It is called iron oxide. Also, when something burns it is always a chemical change.
Maria and Kai are studying changes in science. Everyone on class had an experiment to perform. Maria and Kai placed 25 milliliters of white vinegar in a plastic bottle. They poured 5 grams of baking soda into a balloon and then carefully attached the balloon over the opening of the bottle with the vinegar. The white vinegar foamed up with lots of bubbles. The picture shows what happened to the balloon. Based on these observations, what kind of change took place during the students' experiments?
Chemical Change
300
A small bottle of water is left on the shore of a very large lake on an extremely cold winter night. What is MOST LIKELY to be observed the next morning?
The bottle of water has become solid but the lake has not.
300
Justine made a mixture of strawberries, raspberries, and blueberries. Which physical property of the fruits changed?
None
300
What type of change is happening with this egg?
Chemical Change
400
A student places a lidded pot of water onto a burner on the stove. They turn the stove burner on and set it to medium-high. The student watches and makes observations.
Student Observations:
1. The water starts to boil
2. The water becomes a gas
3. The gas can be seen as steam as it escapes from under the lid of the pot
4. The escaped gas does not keep a shape and appears to quickly disappear in the room
The student claims that changing the temperature of the water causes a physical change that turns water into water vapor. Which argument BEST supports the student’s claim?
- A) Water vapor forms because heat is removed, causing the particles to move slower. This makes the water change its shape.Water vapor forms because heat is removed, causing the particles to move slower. This makes the water change its shape.
- B) Water vapor forms because heat is removed, causing the particles to move slower. This changes the water from a liquid to a gas.Water vapor forms because heat is removed, causing the particles to move slower. This changes the water from a liquid to a gas.
- C)Water vapor forms because heat is added, causing the particles to move faster. This makes the water change from a liquid to a gas.Water vapor forms because heat is added, causing the particles to move faster. This makes the water change from a liquid to a gas.
- D) Water vapor forms because heat is added, causing the particles to move faster. This changes the color of the water making it transparent.
C) Water vapor forms because heat is added, causing the particles to move faster. This makes the water change from a liquid to a gas.
400
Which of these actions causes a physical change?
- Burning a log
- Cooking an egg
- Rusting of a metal pipe
- Crushing an aluminum can
Crushing an aluminum can
400
What is causing the egg to change the most?
An increase in temperature
500
Heating and cooling water can change its state.
Which phase of water is coldest?
Ice
500
Matter can change: the changes can be physical or chemical. When a physical change happens, nothing new is formed. During a physical change, matter changes form; it can be crushed or torn or change state. When a chemical change occurs, something new is formed. For example, a piece of iron can rust. The rust is the new substance that is formed. It is called iron oxide. How can you tell if a chemical change has taken place? There are certain observations you can make:
1. temperature change
2. color change
3. gas or bubbles produced
4. an odor is created
5. combining two liquids forms a solid called a precipitate.
Students in science class watched as their teacher demonstrated various changes. Picture A. shows a strip of magnesium ribbon, a silver metal, in a test tube of hydrochloric acid. Bubbles are forming as the metal ribbon disappears. Also, the test tube feels warmer. Picture B. shows a container of water being heated and bubbles forming as the water bubbles.
Which picture illustrates a chemical change? Explain
Picture A. Gas bubbles are produced and there is a temperature change.