10 most difficult Earth riddles A list of Earth related questions that are most often answered incorrectly Geology quiz What is the most common element (by mass) forming the planet Earth?Iron is most abundant in the Earth's outer and inner core, and it is the fourth most common element in the Earth's crust.very hard 29% carboncarbon28%oxygenoxygen21%ironiron29%siliconsilicon20%Created by: globalquiz.org. Statistics based on 9304 answers in 3 languages »elements riddles » What is the tallest mountain in the world, when measured from its base?Mauna Kea is a dormant volcano on the island of Hawaii. Standing 4,207 m above sea level, its peak is the highest point in the state of Hawaii. Most of the mountain is underwater; when measured from its oceanic base, Mauna Kea is over 10,000 m tall and is the tallest mountain on Earth.very hard 33% Mount EverestMount Everest29%Mount KilimanjaroMount Kilimanjaro24%Mauna KeaMauna Kea33%Gyachung KangGyachung Kang12%Created by: Ninjai. Statistics based on 687 answers in 3 languages »mountains riddles » Where is the saltiest lake in the world?In Antarctica. With a salinity level of over 40%, Don Juan Pond is the saltiest of the Antarctic lakes. This salinity allows the pond to remain liquid even at temperatures as low as −50 °C (−58 °F) due to the interference of salts with the bonding of water molecules. Don Juan Pond was discovered in 1961 by George H. Meyer.very hard 33% in Antarcticain Antarctica33%In AustraliaIn Australia6%in Israelin Israel43%in Turkmenistanin Turkmenistan16%Created by: Tschuka. Statistics based on 1400 answers in 3 languages »salt riddles » What is the rarest metal in the Earth's crust?Rhenium is a chemical element with symbol Re It is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an estimated average concentration of 1 part per billion (ppb), rhenium is one of the rarest elements in the Earth's crust. Discovered in 1908, rhenium was the second-last stable element to be discovered. It was named after the river Rhine in Europe. hard 42% GoldGold8%RheniumRhenium42%PlatinumPlatinum27%ZirconiumZirconium21%Created by: Tschuka. Statistics based on 3924 answers in 3 languages »metals riddles » In which month is the Earth closest to the Sun?In January. Earth's perihelion occurs around January 3, and the aphelion around July 4. The distance change is about 3.5%, which gives 6.9% increase in solar energy reaching the Earth at perihelion relative to aphelion. Since the southern hemisphere is tilted toward the perihelion, the southern hemisphere receives more energy from the Sun than does the northern over the course of a year. hard 44% in Januaryin January44%in Marchin March6%in Junein June32%there is no differencethere is no difference15%Created by: globalquiz.org. Statistics based on 15285 answers in 5 languages »hard simple questions riddles » If Earth's radius was larger by 1 meter, how much longer would its equator be?By approx 6 meters. For each circle, the length of the circumference is c=2πr. Hence, if a radius grows by 1 meter, the circumference grows by 2 π meters - no matter what the initial value of radius was.hard 46% by approx 6 metersby approx 6 meters46%by approx 6 kilometersby approx 6 kilometers17%by approx 60 kilometersby approx 60 kilometers20%by approx 6000 kilometersby approx 6000 kilometers15%Created by: SpikeMe. Statistics based on 30507 answers in 2 languages »math riddles » What object collided with Earth according to the giant impact hypothesis?A planet. According to the giant impact hypothesis Earth once collided with a planet of Mars size usually referred to as Theia, a titaness of Greek mythology, mother of Selene - Moon goddess, which is to reflect the believe the collision was an origin of the Moon. hard 47% a cometa comet10%a moona moon8%an asteroid an asteroid 33%a planeta planet47%Created by: smyru. Statistics based on 8038 answers in 2 languages »universe riddles » After what is the Jurassic period named?A mountain range in Switzerland. The Jurassic period is named for the Jura Mountains in between France and Switzerland, where many fossils have been found.hard 48% a type of ancient lizarda type of ancient lizard12%a mountain range in Switzerlanda mountain range in Switzerland48%a type of coal formed in that perioda type of coal formed in that period15%Latin for 'before mammals'Latin for 'before mammals'24%Created by: MarcusX. Statistics based on 14147 answers in 2 languages »Switzerland riddles » What is the current geological epoch?Holocene. The Holocen is the youngest, contemporary epoch.The Holocene encompasses the growth and impacts of the human species worldwide, including all its written history, development of major civilizations, and overall significant transition toward urban living in the present. hard 52% HoloceneHolocene52%OligceneOligcene16%PliocenePliocene16%MioceneMiocene14%Created by: Tschuka. Statistics based on 439 answers in 2 languages »geology riddles » What part of the Earth's surface is dry land?29,2%. It is currenlty 29.2% - but it may decrease in the near future due to global warming and sea level rise.hard 54% 29,2%29,2%54%33,6%33,6%28%38,4%38,4%11%42,1%42,1%5%Created by: Krzysztof Moskal. Statistics based on 8230 answers in 2 languages »water riddles » Play geology quiz and see all the questions.