Answer:
A. Continental crust is less dense than oceanic crust.
Explanation:
Earth's crust can be divided into two categories, oceanic and continental. More of the surface is covered by oceanic crust, but because ocean crust is thinner than continental crust, the volume of the latter is significantly greater.
Oceanic crust is also denser than continental crust as it is made up of basaltic rock, whereas it's continental counterpart contains a type of less dense rock called felsic.
Two of the major environmental problems facing Central America, South America, and the Caribbean are pollution, and water shortages
The inner core is the dense sphere of solid iron and nickle at the center of the earth.
Answer:
A crystal face tends to be dull and rugged where a cleavage plane (most commonly seen in mica) is smooth and shiny, only being dull towards the edges it splits.
Igneous rock are formed by the cooling and crystallization of molten rock and are formed by the cooling of magma above earth's surface.
Let's look into the statements one by one:
Igneous rocks are formed only from material ejected during a volcanic eruption.
-This is not true because igneous rock can also be formed by the cooling down of magma inside a volcano or magma that was trapped in the crack of crust.
Igneous rocks are formed by the cooling and crystallization of molten rock.
-This is correct.
Igneous rocks are produced by the weathering and transport of pre-existing rocks.
-This is incorrect as igneous rock is formed by volcanism. The rock that are formed with the statement is sedimentary rock.
Igneous rocks are formed by the cooling of magma above earth's surface and lava below the surface.
-This is correct. Both intrusive and extrusive volcanic activity forms igneous rock after cooling down.
Igneous rocks are formed by recrystallization
-This is not true as recrystallization does not take place in the formation of the igneous rock. The rock formed by recrytillization is metamorphic rock.
Therefore,the igneous rock are formed by the cooling and crystallization of molten rock and are formed by the cooling of magma above earth's surface.
Hope it helps!
