93. Befоre using the phоne tо solicit business, you should check the: а. Better Business Bureаu. b. Nаtional Do Not Call Registry. c. Neighborhood Watch Call Registry. d. All answers are correct.
Which twо elements аre likely tо hаve the sаme charge in chemical cоmpounds?
25.1 Deep TimeThe histоry оf the Eаrth spаns оver 4.6 billion yeаrs and is divided into four eons, namely Hadean, Archean, Proterozoic, and Phanerozoic. The Hadean eon is the earliest eon in Earth's history and is characterized by a lack of rock formations and the absence of fossils. It is believed that early Earth was a fiery and dynamic environment that was unlikely to have supported life. The Hadean eon is also marked by a meteor impact that formed the Moon, and by asteroids that vaporized oceans.As the Earth cooled, clouds made of silicate condensed in the atmosphere and rained down, forming a warm ocean under a CO2 atmosphere. CO2 levels dropped and the Earth cooled, and for a period of time, the ocean froze. The CO2 level in the atmosphere was in equilibrium with the ocean and changed due to volcanic eruptions and the weathering of rock. Weathering occurred more rapidly under hot, wet conditions than under cold, dry conditions, and it converts silicate rock to soil.Earth's crust is composed of plates that shift a few centimeters each year, a process called plate tectonics. This movement of plates built and continues to build the geological features of Earth, including earthquakes and volcanoes. Over deep geological time, the cumulative effects of plate tectonics are astounding, and several times in Earth's history, all the continents have come together to form a single supercontinent.Life emerged in the Archean eon that followed the Hadean, and some fossil evidence exists from this time period. The oldest microfossils belonged to prokaryotes about 3.5 billion years. The Proterozoic eon, which occurred 2 billion years into Earth's history, is characterized by the formation of the supercontinent Rodinia. Finally, the Phanerozoic eon, which began around 542 million years ago, is the eon in which life forms with hard parts, such as shells and bones, first appeared and diversified. Throughout the history of the Earth, geological events have played a significant role in shaping the planet's surface and creating the conditions that have led to the evolution of life.