1. Atoms and molecules PS5 2.08

15. Where in the atom are electrons found?

18. There are 90 natural elements. Elements are what we call the different kinds of atoms. The thing that makes elements different from each other is the number of protons in the nucleus.

19. Hydrogen has one proton

20. Helium has two protons protons

21. Carbon has 6 protons

22. Iron has 26 protons

23. Gold has 79 protons

24. The Periodic Table of Elements lists all the elements. They are in order according to their number of protons.

25. What is the chart that scientists use to list all the elements?

27. Each square on the Periodic Table shows one element.

28. Each square on the Periodic Table shows information about that element. Helium

29. The different number of protons in elements (the atomic number) gives each one different properties or characteristics.

30. Hydrogen, with one proton, is a very light gas.

31. There were once huge airships filled with hydrogen that could float like balloons.

32. But hydrogen gas has the property of being highly flammable. It can explode with one little spark.

33. Helium, with two protons, is also a very light gas that works well in balloons. But helium is safe. It won’t burn at all.

34. What could happen if party balloons were filled with hydrogen gas instead of helium?

35. What could happen if party balloons were filled with hydrogen gas instead of helium?

36. They could have made new airships filled with helium instead of hydrogen.

37. But after the Hindenburg exploded people didn’t want to fly in gas filled airships anymore.

38. There are 90 natural elements. Each element has a different number of protons. Each element has different properties.

39. What do we call the different types of atoms?

42. What two things make the elements different from each other?

45. There are 90 different elements but there are a lot more than 90 different kinds of “stuff.”

46. There are 90 different elements but there are a lot more than 90 different kinds of “stuff.” There are millions of different kinds of stuff.

47. There are 90 different elements but there are a lot more than 90 different kinds of “stuff.” There are millions of different kinds of stuff. How can they all come from only 90 elements?

48. Just like 26 different letters in the alphabet can be put together in different ways to make thousands of words….. ABCDEFGHIJKLMNOPQRSTUVWXYZ c + a + t = cat

49. 90 different elements can be put together in different ways to make millions of different kinds of stuff….. Hydrogen + Oxygen = water (H 2 O)

58. What is the smallest particle of an element?

60. What is the smallest particle of a compound?

62. How many atoms are in a molecule?

65. A compound can have totally different properties than the elements that make it.

66. One property of hydrogen is that it is highly flammable (burns easily).

67. Oxygen is an element that also has the property of flammability.

71. Sodium is an element. Sodium is also a metal.

72. A property of pure sodium is that it reacts violently when it comes in contact with water.

73. Chlorine is an element. Pure chlorine is a poisonous green gas. You sure wouldn’t want pure chlorine in your food.

74. Chlorine is an element. Pure chlorine is a poisonous green gas. You sure wouldn’t want pure chlorine in your food.

75. Chlorine is an element. Pure chlorine is a poisonous green gas. If something has the property of being poisonous, you sure wouldn’t want to put it in your food.

76. But sodium and chlorine together make a compound that we eat everyday. Na + Cl NaCl

80. CO 2 has no energy in it. H 2 O has no energy in it. But C 6 H 12 O 6 (sugar) is the chemical energy that all living things must have to live and grow.

81. CO 2 has no energy in it. H 2 O has no energy in it. But C 6 H 12 O 6 (sugar) is the chemical energy that all living things must have to live and grow.

82. CO 2 has no energy in it. H 2 O has no energy in it. But C 6 H 12 O 6 (sugar) is the chemical energy that all living things must have to live and grow.

83. New compounds can have properties that are very different from properties of the elements or compounds that made them.

87. The images from these instruments show that atoms and molecules are usually found in well ordered arrays , which means they are arranged neatly.

88. Atoms and molecules are found in well ordered arrays.

89. Atoms and molecules are found in well ordered arrays.

90. Atoms and molecules are found in well ordered arrays.

91. Atoms and molecules are found in well ordered arrays.

92. Atoms and molecules are found in well ordered arrays.

93. Atoms and molecules are found in well ordered arrays.