9. a magmas viscosity is directly related to

Silica content.

Magma is a fluid of molten rock, that is formed under pressure and heat inside the earth. It remains inside the erupting body, until eruption takes place. When it comes out as a result of volcanic eruption it is known as lava. Viscosity can be defined as the ability of a substance or material to resist it's flow. A magma's viscosity is directly related to it's silica content. Higher the silica content in the magma have higher viscosity than the magma with low silica content.  

americans began to notice growing differences between the northern and southern sections of the country. there were more people living in cities in the north, which made it more urban. more people lived on farms in the south, which made it more rural. while many people were farmers in the northern states, there were now other ways to make a living, such as working in mechanical cotton gins factories manufacturing cloth, tools and other goods. people in the north supported high tariffs on goods imported from europe because the extra cost encouraged people to “buy american” instead. in the southern states, planters did not like tariffs because they sold most of their production to europe and bought their tools from there as well. southerners believed the protective tariff was something that only northern factory owners keep their profits high. so the southern politicians came up with an idea. they would opt out. they would simply ignore the protective tariff. it was ‘null and void’ in south carolina. the state would not collect the taxes on goods imported into south carolina, no matter what the president said they had to do. this decision led to the nullification crisis.