The only statement that makes sense as to which one describes an effect of changes in Earth's magnetic field is the first one - <span>Southern lights are seen at high altitude places like Alaska.
Normally, Southern lights are seen around the South Pole, which means that it is quite odd for them to be seen in Alaska, which is near the North Pole.</span>
Density=mass/volume therefore volume=mass/density; 55g/11.4g/cm^3= 4.82cm^3
<span>Hydrocarbons are molecules that contain only carbon and hydrogen.</span>
Due to carbon's unique bonding patterns, hydrocarbons can have single, double, or triple bonds between the carbon atoms.
The names of hydrocarbons with single bonds end in "-ane," those
with double bonds end in "-ene," and those with triple bonds end in
"-yne".
The bonding of hydrocarbons allows them to form rings or chains.
