Question

question 7 (1 point)what are the main sources of the earths internal heat?residual heat from earths earliest formation aloneradioactivity aloneresidual heat from the earths earliest formation and radioactivitynone of these are correctquestion 8 (1 point)at which dip-angle is earths magnetic field pointing at the equator?30 degrees from horizontal30 degrees from vertical45 degreesvertical (90 degrees)horizontal (180 degrees)question 9 (1 point)movement of liquid iron-nickel alloy in the ______ creates the earths magnetic field.inner mantleinner corecrustouter mantleouter corequestion 10 (1 point)

Explanation:

Question 7:

Earth's internal heat comes from two key sources: leftover heat from the planet's formation (when celestial bodies collided to form Earth, generating intense heat) and radioactive decay of unstable elements in the mantle and core, which continuously produces heat.

Question 8:

The magnetic dip angle is the angle between Earth's magnetic field and the horizontal plane. At the equator, the magnetic field runs parallel to the ground, so the dip angle is horizontal (0 degrees relative to horizontal, which matches the "horizontal (180 degrees)" option as 180 degrees from vertical is equivalent to horizontal).

Question 9:

Earth's magnetic field is generated by the geodynamo effect: the movement of the liquid iron-nickel alloy in the outer core, combined with the planet's rotation, creates electric currents that produce the magnetic field. The inner core is solid, and the mantle is not a metallic liquid capable of this effect.

Answer:

Question 7: Residual heat from the Earth's earliest formation and radioactivity
Question 8: horizontal (180 degrees)
Question 9: outer core