The document discusses various chemical reactions, illustrating the concept that certain processes, like baking a cake or spoiling milk, cannot be reversed. It emphasizes that carbon dioxide bubbles cause pockets in bread and confirms the irreversibility of baking. Overall, it asserts the permanence of chemical changes through examples.

1. By Mrs. Burch
10/10/18

2. https://youtu.be/37pir0ej_S
E

4. New
substance
Old
substance

13. True!

18. The pockets are caused by carbon dioxide bubbles
forming.

20. The bread can’t be turned back into flour, milk, and
butter.

48. melting ice

49. melting ice

50. cake baking

51. cake baking

52. rotting orange

53. rotting orange

54. popping a balloon

55. popping a balloon

56. boiling water

57. boiling water

58. frying eggs

59. frying eggs

60. burning wood

61. burning wood

62. crumpling paper

63. crumpling paper

64. milk spoiling

65. milk spoiling

67. Answer: chemical
reaction

69. Answer:
True!

70. You can’t un-bake the cake.

72. Answer:
False!