A scientist is analyzing an unknown material. When this material is heated, it gives off a gas, and a solid residue remains. No, the unknown material is not an element. An element cannot be broken down into simpler substances, but the unknown substance breaks down into a solid and a gas. A pure element could react with oxygen to make a solid or a gas, but if both a solid and a gas are formed, then the substance must have at least two different components.
Apparent magnitude is how bright a star appears from Earth.
Absolute magnitude is how bright the star would appear from a standard distance. A permanent magnet always has a magnetic field and does not need energy input to maintain the field. An electromagnet only has a magnetic field when a current flows through it, so the field of an electromagnet can be turned on and off, varied in strength, or reversed. Describe how it works. The dipole force is an electrostatic force between partial charges which form on molecules due to unequal sharing of electrons.