Across |
1. | A chemical reaction in which oxygen combines with another compound to form water and CO2 is called a _________ reaction. |
4. | The 3 elements created out of the Big Bang were hydrogen, helium and ___________. |
6. | A molecule with a positive or negative charge. |
8. | The known universe is comprised of matter and ___________. |
12. | The second most common element in the Earth's crust (27.7%) is ___________. |
15. | Type of reproduction involving a male and female parent. |
16. | Conifers are classified as ___________. |
19. | It is important for seeds to germinate far from the parent plant so they do compete for ___________. |
20. | Sodium chloride is more commonly known as _______________. |
21. | A chemical reaction in which new molecules form is called a ___________ reaction. |
23. | Three forms of sexual reproduction in plants are by spores, flowers, and _________. |
24. | Pollination of a flower leads to ___________. |
25. | The periodic table has __________ rows |
26. | Flowering plants are classified as __________. |
29. | The double strip of elements listed at the bottom of the periodic table. |
30. | The science of building machines at the atomic level. |
33. | The second most abundant metal found in the Earth's crust (5%) is _________. |
36. | The science of studying behavior of sub-atomic particles. |
37. | Strawberry plants are an example of _________ reproduction. |
38. | Animals, water and wind are the main agents of seed ___________. |
41. | A chemical reaction in which complex molecules are broken down into simpler ones is called a ___________ reaction. |
43. | Electrons orbit the nucleus in layers known as ________. |
45. | When a flower pollinates itself it is known as ______________. |
46. | The number of protons in an element is the same as its _________ number. |
47. | Particles that transmit electricity by flowing through wires and circuits. |
50. | Name of the element primarily used in nuclear technology. |
51. | Electrons that orbit an atom in its outermost orbit are called _________ electrons. |
53. | Pollen grains contain __________, sex cells critical for fertilization. |
54. | Gymnosperms do not produce __________. |
58. | Scientist who discovered the nucleus. |
59. | The Hindenberg burned because it was filled with pure _________, which will combust in the presence of oxygen and a spark. |
61. | The most abundant metal (8%) found in the Earth's crust is __________. |
65. | The horizontal rows are called __________. |
67. | Type of bond occurring when a non-metal bonds with a non-metal. |
69. | Particle in the nucleus with a neutral charge. |
71. | Family of metals known to react violently with water. |
73. | Atomic number is the number of __________. |
75. | Pollen grains land on the ___________ of the pistil. |
76. | Type of reproduction involving only one organism. |
77. | Mosses, ferns, and liverworts reproduce by means of __________. |
78. | The male reproductive organ of plants. |
79. | Once the zygote begins dividing, it develops into a __________. |
80. | Positively charged particle found in the nucleus. |