Explanation:
The molecules of solids are shrinked in there normal state . but as a heat energy is produced , the molecules starts curating fast and fast as temperature goes up . since they vibrate , they hit and collide each other breaking the bondings this increases the surface of area of the solid , and molecules consumes that space and they expand .
Answer: D) helium.
Explanation:
Nuclear fission is a process which involves the conversion of a heavier nuclei into two or more small and stable nuclei along with the release of energy.

Nuclear fusion is a process which involves the conversion of two small nuclei to form a heavy nuclei along with release of energy.
Example: 
Thus when deuterium and tritium , the two isotopes of hydrogen are fused, a heavier nuclei helium is being formed from two smaller nuclei releasing a neutron.
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<u>A</u><u>n</u><u>s</u><u>w</u><u>e</u><u>r</u><u>:</u><u>-</u></h2>
<em>The female part is the pistil. The pistil usually is located in the center of the flower and is made up of three parts: the stigma, style, and ovary. The stigma is the sticky knob at the top of the pistil. It is attached to the long, tubelike structure called the style.</em>
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<em><u>H</u></em><em><u>o</u></em><em><u>p</u></em><em><u>e</u></em><em><u> </u></em><em><u>I</u></em><em><u>t</u></em><em><u> </u></em><em><u>W</u></em><em><u>i</u></em><em><u>l</u></em><em><u>l</u></em><em><u> </u></em><em><u>H</u></em><em><u>e</u></em><em><u>l</u></em><em><u>p</u></em><em><u> </u></em><em><u>Y</u></em><em><u>o</u></em><em><u>u</u></em><em><u>!</u></em></h3>