Answer:
Oil shale is a form of sedimentary rock that contains kerogen, which is released as a petroleum-like liquid when the rock is heated. Tar sands are a combination of clay, sand, water and bitumen, which is a heavy hydrocarbon.
Additional info:
The term oil sands refers to a particular type of nonconventional oil deposit that is found throughout the world. Oil sands, sometimes referred to as tar sands, is a mixture of sand, clay, other minerals, water, and bitumen. The bitumen is a form of crude oil that can be separated out from the mixture.
The primary distinction between crude or conventional oil and shale oil is the way it collects. The oil in shale is typically found in smaller batches. As a result, shale oil often needs to be fractured so that the oil trapped within the shale can be recovered.
Mass is measured by using a balance comparing a known amount of matter to an unknown amount of matter. Weight is measured on a scale.
The Precambrian era envelopes the major bulk of the history of the Earth, beginning from the creation of the planet approx 4.5 billion years ago and terminating with the origination of composite, multicelled forms of life approximately 4 billion years after.
The Precambrian refers to the earliest of the geologic ages that are signified by the distinct layers of sedimentary rock. The Earth was about more than six hundred million years old when life started. The planet had cooled down from its native molten state, creating a solid crust and oceans formed by water vapor in the atmosphere.
At about three billion years ago, the atmosphere of the Earth was virtually devoid of oxygen. At approximately 2.4 billion years ago, oxygen was discharged from the seas as a waste product of photosynthesis by cyanobacteria. The levels of the gas slowly raised, attaining about 1 percent around two billion years ago.
Approximately 800 million years ago, the levels of oxygen attained about 21 percent and started to breathe life into more composite species. The oxygen-rich ozone layer was also created, protecting the surface of the Earth from the harmful solar radiation.
Are there suppose to be choices?
Cuando el hielo se calienta, comienza a derretirse y a formar agua, esto es progresivo
