The sun is a very typical star. It is neither very hot or cold, big or small, or old or young. It is simply the closest star to us. The sun is composed of hydrogen, <1>, and traces of other elements. All of this material is in the form of plasma -- where the electrons have been knocked free from the nuclei. The temperature at the sun's $location is <2> K.
Many interesting effects can be seen associated with the three layers of the solar atmosphere: photosphere, chromosphere, and corona. The alternating light and dark areas caused by convection are known as <3> and are seen on the sun's <4>. Spicules (think spikes) are found on the sun's <5>. The solar wind consists of particles streaming away from the sun's <6>. Sunspots are found on the <7> and are dark because they are <8> than the surrounding regions.
Spectroscopists who regularly study the photosphere observe a(n) <9> spectrum while those who observe the chromosphere during a solar eclipse observe a(n) <10> spectrum.@ qu.1.1.algorithm= $num=$rint(2); $location=switch($num,"surface","core"); $temp=switch($num,"6000","15 million"); $badtemp=switch($num,"15 million","6000");@ qu.1.1.blank.1=helium,lithium,berrylim,copper@ qu.1.1.blank.2=$temp,$badtemp,20 trillion, 80 billion@ qu.1.1.blank.3=granulation,limb darkening,the Zeeman Effect,solar activity@ qu.1.1.blank.4=photosphere,chomosphere,corona@ qu.1.1.blank.5=chomosphere,photosphere,corona@ qu.1.1.blank.6=corona,chomosphere,photosphere@ qu.1.1.blank.7=photosphere,chomosphere,corona@ qu.1.1.blank.8=cooler,hotter@ qu.1.1.blank.9=absorption,continuous,emission@ qu.1.1.blank.10=emission,absorption,continuous@ qu.1.1.grader.1=menu@ qu.1.1.grader.2=menu@ qu.1.1.grader.3=menu@ qu.1.1.grader.4=menu@ qu.1.1.grader.5=menu@ qu.1.1.grader.6=menu@ qu.1.1.grader.7=menu@ qu.1.1.grader.8=menu@ qu.1.1.grader.9=menu@ qu.1.1.grader.10=menu@ qu.1.2.mode=Blanks@ qu.1.2.editing=useHTML@ qu.1.2.name=The Visible Sun@ qu.1.2.question=
The sun is a very typical star. It is neither very hot or cold, big or small, or old or young. It is simply the closest star to us. The sun is composed of hydrogen, <1>, and traces of other elements. All of this material is in the form of plasma -- where the electrons have been knocked free from the nuclei. The temperature at the sun's $location is <2> K.
Many interesting effects can be seen associated with the three layers of the solar atmosphere: photosphere, chromosphere, and corona. Sunspots are found on the <3> and are dark because they are <4> than the surrounding regions. Spicules (think spikes) are found on the sun's <5>. The alternating light and dark areas caused by convection are known as <6> and are seen on the sun's <7>. The solar wind consists of particles streaming away from the sun's <8>.
Spectroscopists who study the chromosphere during a solar eclipse observe a(n) <9> spectrum while those who regularly study the photosphere observe a(n) <10> spectrum.@ qu.1.2.algorithm= $num=$rint(2); $location=switch($num,"surface","core"); $temp=switch($num,"6000","15 million"); $badtemp=switch($num,"15 million","6000");@ qu.1.2.blank.1=helium,lithium,berrylim,copper@ qu.1.2.blank.2=$temp,$badtemp,20 trillion, 80 billion@ qu.1.2.blank.3=photosphere,chomosphere,corona@ qu.1.2.blank.4=cooler,hotter@ qu.1.2.blank.5=chomosphere,photosphere,corona@ qu.1.2.blank.6=granulation,limb darkening,the Zeeman Effect,solar activity@ qu.1.2.blank.7=photosphere,chomosphere,corona@ qu.1.2.blank.8=corona,chomosphere,photosphere@ qu.1.2.blank.9=emission,absorption,continuous@ qu.1.2.blank.10=absorption,continuous,emission@ qu.1.2.grader.1=menu@ qu.1.2.grader.2=menu@ qu.1.2.grader.3=menu@ qu.1.2.grader.4=menu@ qu.1.2.grader.5=menu@ qu.1.2.grader.6=menu@ qu.1.2.grader.7=menu@ qu.1.2.grader.8=menu@ qu.1.2.grader.9=menu@ qu.1.2.grader.10=menu@