For question #17, use the following picture:

17. what element is this? how do you know? (page 495 and periodic table pages 500-501)

for questions 18-21, use the information on pages 590-592 and page 567. in each space, classify the reaction type.
18. 2libr + pb(no3) pbbr2 + 2lino3
19. fe + 2hcl fecl2 + h2
¬¬¬20. cao + h2o ca(oh)2
21. nicl2 ni + cl2

some think that theories become laws, but theories and laws have separate and distinct roles in the scientific method. a law is a description of an observed phenomenon in the natural world that hold true every time it is tested. it doesn't explain why something is true; it just states that it is true.

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answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.

im srry but ur wrong the answer is d a smooth rock, some red dirt, and an empty bird's nest.