barry is applying the principles of relative dating to a building that has been constructed. analyzing a section of the building, barry

says that the lowest part of the section must have been constructed

the parts above it were constructed. he

bases this conclusion on the principle of

. also, looking at a crack forming in the building wall, he says

that the crack must be

the wall. barry used the principle of

to arrive at this

conclusion.

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a mid-ocean ridge or mid-oceanic ridge is an underwater mountain range, formed by plate tectonics. this uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.a geomagnetic reversal is a change in a planet's magnetic field such that the positions of magnetic north and magnetic south are interchanged.

because the two particles have an equal charge, the charges will cancel out and give the atom an overall charge of 0. so, if at atom has 35 protons in the nucleus, we could expect it to have 35 electrons orbiting that nucleus.