Changes 1
Name 3 examples of chemical change?
iron rust,gas burning, eggs cooking, bread rising
A student says, “Melting butter is a chemical change because the butter looks different.” Do you agree or disagree? Explain your reasoning.
disagree because the properties of the butter is the same
Thermal conductivity is an essential part of our daily lives. What does a conductor and an insulator do not have in common?
a) A conductor does not allow electricity to flow freely through it, whereas an insulator does.
b) An insulator does not allow electricity to flow freely through it, whereas a conductor does.
c) A conductor is not magnetic, while an insulator is.
d) An insulator is not magnetic, whereas a conductor is.
b) An insulator does not allow electricity to flow freely through it, whereas a conductor does.
Dr. taylor takes a piece of notebook paper from her desk. As a demonstration she tears the paper into 14 pieces. After Dr. Taylor tears the paper, what would you expect to happen to the mass of the torn pieces?
The mass of all the torn pieces of the paper should equal the mass of the original piece of notebook paper. The matter was not destroyed, it just changed form after it was torn into pieces.
Chemical change
A candle is burning. Which part of the process is a physical change, and which part is a chemical change?
The wick burning is chemical and the wax melting
You are given three changes to investigate: cutting paper, burning paper, and folding paper. Which are physical and which are chemical? Explain your reasoning.
cutting paper and folding paper are physical change because no new substances are form while burning paper is a chemical change
Leaves change colour because their chemical makeup is changing. What change am I?
Chemical change a change in color.
Paper is still paper if it is ripped in half and crumpled up. What am I?
What is a physical change?
What is a Physical change
What happens to the mass of matter during a chemical change, according to the Law of Conservation of Mass?
stays the same
what doesn't change into anything new
a substance
Which of the following is a chemical change that takes place because of an increase in temperature?
A. Food stays fresh in a refrigerator.
B. Wind moves soil to other places.
C. Batter bakes into a cake
D. Snow falls in the winter
C.Batter bakes into a cake
Mason measured the mass of a closed beaker containing several ice cubes. The mass was 225 g. An hour and a half later, Mason returned to find that the ice had melted. What type of change occurred, and what would the measured mass be now?
A. Physical change, 225 g
B. Chemical change, 125 g
C. Physical change, 25 g
D. Chemical change, 225 g
A. Physical change , 225g
An experiment was performed in which a crystalline substance was added to a beaker filled with a liquid at room temperature. The observations made during the experiment were as follows: which is not a sign of a chemical change
1. The crystals dissolved.
2.A precipitate formed.
3.The bottom of the beaker felt warm to the touch.
4.Bubbles formed in the water.
1. crystal dissovling
What are two signs that a chemical change has taken place?
bubbles, odour, light, precipitate,
what are the main states of mater
solid,liquid,gas
When a substance goes through a chemical change, it forms a new substance that has different physical and chemical properties. Often, chemical changes are caused by changes in temperature. Which of the following is a chemical change caused by a change in temperature?
A. Cooking an egg B. Freezing a popsicle
C. Boiling water D. Melting ice cream
A. cooking an egg
In a physical change the appearance of matter changes, but its chemical composition remains__________
Remains the same.
what is the difference between a physical change and chemical change
Chemical change there is change in the substance and physical change there is change in the appearance
Melting snow/dissolving sugar is an example of ?
What is physical change?
Melting snow/dissolving sugar is an example of ?
What is physical change.
Hannah added a silvery white metal to a beaker of cold water and noticed that gas bubbles were given off and a different substance formed. When she repeated the activity with hot water she noticed the gas bubbles were released much more rapidly. Explain why the reaction occurred faster in hot water?
When you raise the temperature of water it causes the particles (or atoms) to move faster which causes more and faster collisions with the metal making the reaction occur faster.
There are characteristics that differentiate a chemical change from a physical change. Which statement describes a physical change?
A. Iron combines with oxygen to form rust.
B. Lead is heated and melts into a viscous liquid.
C. Sodium metal reacts explosively with oxygen.
D. Calcium is added to acid and hydrogen gas is produced.
B. lead heated and melts
Joseph wants to set up a demonstration that shows the law of conservation of mass. Which of these experimental setups should Joseph choose?
D. Sealing ice in a clear bottle and allowing it to melt