On 2003 August 27, Mars was in opposition as seen from the Earth. On 2005 July 14 (687 days later), Mars was in western quadrature as seen from the Earth. What was the distance of Mars from the Sun on these dates, measured in AU

In positive numbers less than 1, the zeros between the decimal point and a non-zero number are blank significant

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.

An isotope undergoes radioactive decay by emitting radiation that has a –1 charge. what other characteristic does the radiation have?