Michigan Test for Teacher Certification (MTTC) Secondary Integrated Science Practice test

How was the Earth formed according to scientific understanding?

1. From solidified gases after the sun was created

2. By the collision of meteorites

3. From the vaporization of water

4. By divine creation

The correct answer is: From solidified gases after the sun was created

The scientific understanding of Earth’s formation is centered on the theory of planetary accretion, which posits that the planet formed from the dust and gas surrounding the early Sun. Initially, the material in the solar nebula, including solid particles and gases, coalesced under the force of gravity. As these materials aggregated, they formed larger bodies known as planetesimals, which eventually became protoplanets. Earth is one of these protoplanets that continued to gather mass through collisions and the gravitational pull of surrounding debris. The concept of solidified gases is a somewhat misunderstood aspect of the formation process. Instead, it’s relevant to recognize that the primordial Earth was originally molten; as it cooled, various elements solidified to form the crust, while gases were expelled into the atmosphere as volcanic activity ensued. However, stating that Earth formed from solidified gases simplifies and misrepresents the complexity of the accretion and cooling processes that characterized its early history. The other options do not adequately capture the comprehensive scientific explanation. While meteorite collisions contributed to the growth of planets and played a role in delivering water and other materials to Earth, they do not reflect the primary mechanism of the planet's initial formation. Vaporization of water is not