Which is the gender of the following Russian words: тетрадь, чай, щи?
Male? Female? Neutral?

Question

Answer

Тетрадь (она/she) - feminine.
Чай (он/he) - masculine.
Щи (они/they) - plural, like "ножницы" (scissors). For example: Будешь щи? Они вкусные!

Answer

The noun, that ends on "и" i or "у" and is singular, can be male, female or neutral. And such nouns are always borrowed words.
беби - m., гризли - m., колибри - f., гуппи - f., кенгуру - f. or m., тори - m. (political party in England), хаки (n.), сиртаки (m. or n.), макИ - m. (French partisan), буги-вуги - m. or pl. I don't think that there is a rule. You need look dictionary. But perhaps колибри and гуппи are female because птица и рыба are female.

Answer

Sorry. I'll better post them apart.      http://lingvopro.abbyyonline.com/en/Search/ru-en

Answer

http://lingvopro.abbyyonline.com/en/Search/ru-en
http://slovar.plib.ru/ 
http://slovarus.info/rus_ef.php

Answer

I'd like to give you links to very good on line dictionaries. The nouns on these dictionaries are always marked with one of the following letters: м. (мужской - masculine), ж. (женский - feminine), ср. or с. (средний - neuter), мн. (множественный - plural).

http://lingvopro.abbyyonline.com/en/Search/ru-en

http://slovar.plib.ru/

http://slovarus.info/rus_ef.php