Author Question: The middle era of the geological history of Mars is called the A) Noachian B) Hesperian C) ... (Read 81 times)

soccerdreamer_17 · **on:** Jul 27, 2018

The middle era of the geological history of Mars is called the

A) Noachian
B) Hesperian
C) Amazonian
D) Phanerozonian

Question 2

Why might we think that silicon would be an obvious alternative to carbon as a building block for biological molecules?

A) it forms the basis of some life forms on Earth
B) it has a similar abundance on Earth to carbon
C) it forms complex molecules like carbon
D) it has a similar electronic structure to carbon, forming a maximum of four bonds and, hence, should have a similar chemistry