It depends on the context. If they preced the name of a continent they do.
Yes, "Eastern" in reference to the eastern United States should be capitalized as it is part of the proper noun.
The phrase eastern US should not be capitalized.
Yes, "Arabs" should be capitalized when referring to the ethnic group or people from the Arab world.
Yes, "Eastern hemlock" should be capitalized as it is a proper noun.
Yes, "Pterodactyl" is supposed to be capitalized as it is a proper noun referring to a specific genus of pterosaur.
Yes, the 'T' in 'The Bahamas' is supposed to be capitalized because "The" is part of the country's official name.
No, "adults" is not typically capitalized unless it is part of a proper noun or at the beginning of a sentence.
Yes, "Arabs" should be capitalized when referring to the ethnic group or people from the Arab world.
Yes. It is a proper noun.
Yes--While the word hemisphere alone is not capitalized, a specific hemisphere (western, eastern, northern or southern) is.
Earth, as in we live on the planet Earth, is supposed to be capitalized. Earth, as in the dirt we walk on, is not supposed to be capitalized.
Usually, yes a phase of the moon is supposed to be capitalized.
No, it shouldn't be capitalized.
No it shouldn't be capitalized.
Yes, "Hindenburg" should be capitalized as it is a proper noun referring to the German airship LZ 129 Hindenburg.
Yes, America should be capitalized.
no
No, but the names of individual languages are capitalized.
Yes, Siamese would be capitalized.