1. Greatest waterfall (in terms of flow rate)   Boyoma (formerly Stanley) Falls   Yosemite Falls   Niagara Falls   Khône Falls   Grande Falls   Hint Half-n-half Clue   2. Largest satellite (natural) of our solar system   Ganymede   Deimos   Sinope   Moon   Phobos   Half-n-half Clue   3. Nearest star to the Earth (other than the Sun)   Proxima Centauri   Alpha Centauri   Dog Star   Great Bear   Andromeda   Half-n-half Clue   4. Hottest planet of our solar system   Venus   Mars   Mercury   Jupiter   Earth   Half-n-half Clue   5. Highest mountain   Kanchenjunga   K2   Mount Everest   Mount Rushmore   Andes   Half-n-half Clue   6. Highest waterfall   Niagara Falls   Khône Falls   Yosemite Falls   Tugela Falls   Angel Falls   Half-n-half Clue   7. Largest active volcano   Etna, Sicily   Mauna Loa, Hawaii   Stromboli, Italy   Mount St Helens, US   Mt Cameroon, Cameroon   Half-n-half Clue