2. I am a noble gas comprising 0.934%, by volume, of the earth’s
atmosphere.

3. I am a transition element found in hemoglobin and rust.

4. I am the element that forms the foundation for the semiconductor
industry.

5. I am an alkali metal whose name is derived from the color of light
emitted by my salts in a flame test.

6. I am an actinide metal named after a very famous scientist who is
best known for developing the equation, E = mc2, which relates mass
and energy.

7. I am a metal with the same name as a well-known North American
coin.