Scientists believe that the earth's core is made mostly of: silicon and oxygen iron and nickel granite and basalt calcium carbonate

iron and nickel

Explanation:

According to the various researches conducted by numerous scientists, the core of the earth is made of "IRON and NICKEL." The Iron forms the inner most park, with a radius of about 750 miles thickness, while the Nickel-Iron alloy forms the outcome, with a radius of about 1,355 miles thickness.

Hence, in this case, the correct answer is " Scientists believe that the earth's core is made mostly of: IRON and NICKEL.

was a long, primarily nonviolent series of events to bring full civil rights and equality under the law to all americans. the era has had a lasting impact on united states society, in its tactics, the increased social and legal acceptance of civil rights, and in its exposure of the prevalence and cost of racism. in the south violence and fraud in southern elections from 1868 to 1876, which had reduced black voter turnout and enabled southern white democrats to regain power in state legislatures across the south