If you were told an atom was an ion, you would know the atom must have a

Amplitude is a measure of a waves a; speed b; distance c; energy d; frequency

The speed of light can be used to measure the

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.