Sound is a wave.
a large boulder falls from an underwater ledge and crashes on the floor of the ocean. a pod of dolphins is 800 meters away. determine how long it takes for the sound of the crash to reach the dolphins. 0.5 sec 0.3 sec 2.3 sec 1.9 sec

Ared apple is illuminated by a blue light the apple will appear

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.

If element x has 99 protons how many electrons does it have