How did railroad expansion make natural resources more available in the united states?

24-karat gold is considered to be pure gold. 18-karat gold is considered to be about 75% gold. what is 18-karat gold considered a mixture rather than a pure substance? a) it has a variable composition of other elements and minerals. b) its color is different than pure gold. c) the gold atoms are not arranged in a repeating pattern. d) it can be melted and transformed into a different substance.

Does manufacturing in the midwest affect the nations economy

How did the mali empire come to an end? a. rulers lost control of gao. b. they were conquered by axum. c. ghana took over their territory. d. sundiata was captured by mansa musa brainliest!