Our solar system formed from a huge cloud of dust and gas called a
a. disk
b. protostar
c. solar nebula
d. planetesimal

The correct answer is C. Solar nebula

Explanation:

According to scientists, the Solar nebula was rotating disk or cloud of dust and gas (mainly hydrogen and helio) that is believed was the origin of our solar system. Indeed, it is estimated the formation of our solar system began 4.6 billion years ago as the solar nebula began contracting forming first the sun in the center and then other elements such as planets. This theory was first proposed in 1734 by Emanuel Swedenborg; however, from the first proposal, multiple models have emerged related to this theory and nowadays, the solar nebula theory is the one that scientist believe explain the formation of our solar system and other solar systems. Thus, our solar system formed from a huge cloud of dust and gas called a solar nebula.

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i think it because equal matrices have equal dimensions, only square matrices can be symmetric. for all indices and . every square diagonal matrix is symmetric, since all off-diagonal elements are zero. in linear algebra, a real symmetric matrix represents a self-adjoint operator over a real inner product space.