yes it is

The Oxford Learner's Dictionaries are an excellent resource. https://www.oxfordlearnersdictionaries.com/definition/english/some_1?q=some 1) If the moon landing was fake SOME scientist from NASA would've exposed it by now. correct - Oxford meaning #5 2) I'm sure you'll find SOME heater that comes with that feature. correct - Oxford meaning #5 3) SOME friend you are! correct - Oxford meaning #6 4) They are going to the country for SOME wedding. correct - Oxford meaning #5

Hi, Im not a native speaker. Those "some"s in your examples sound like "a certain" or "a" to me. Here, I copied some entries from Longman Dictionary for your information. 【some】 ........ 4 used to mean a person or thing, when you do not know or say exactly which: ---- There must be some reason for her behaviour. ----Can you give me some idea of the cost? some kind/type/form/sort of something ---- We can hopefully reach some kind of agreement. 5 （informal） used when you are talking about a person or thing that you do not know, remember, or understand, or when you think it does not matter： ----Some guy called for you while you were gone. ----Just give him some excuse or other. 6 used to say that something was very good or very impressive ----That was some party last night! 7 → some friend you are/some help she was etc

Hi Ashraful, SOME is used for plural and uncountable nouns to express quantity - so your first sentence should read 'some scientists'. The second sentence is unclear - can you provide the context. The 3rd sentence is an idiomatic expression, and the 4th is a very informal use of 'some' as an adjective, here meaning 'unknown and (probably) uninteresting. Hope that helps! Helen