This question is ambiguous and open to interpretation. There are two main ways to interpret "highest":
- Highest Abundance: Which element is most abundant in the universe?
- Highest Atomic Number: Which element has the highest atomic number detected in the universe?
Let's address each interpretation separately.
1. Highest Abundance:
The most abundant element in the universe is Hydrogen.
- Hydrogen accounts for approximately 71% of the mass of the universe and 90% of all atoms.
- It's followed by Helium, which makes up around 27% of the mass.
- All other elements constitute a relatively small percentage.
2. Highest Atomic Number:
This question is more complex because the definition of "detected" needs clarification. Elements with high atomic numbers are generally unstable and decay radioactively. Naturally occurring elements only exist up to a certain atomic number.
- Naturally Occurring Elements: The element with the highest atomic number found naturally on Earth is likely Uranium (U), with an atomic number of 92. Trace amounts of Plutonium (Pu), atomic number 94, can also be found. While these are found on earth, the conditions from which they arise, from Supernovae explosions, means it is likely some, however small, exists in the universe.
- Synthesized Elements: Scientists have created elements with significantly higher atomic numbers in laboratories. These are called synthetic elements. Oganesson (Og), with an atomic number of 118, is the highest atomic number element that has been synthesized. While synthesized elements are not "naturally" occurring, they do exist, albeit briefly and in a laboratory setting.
Therefore, depending on what one accepts as "existing," the answer could be Uranium, Plutonium, or Oganesson. Given the question's ambiguity, naturally occurring elements within the universe is the more probable interpretation.
In Summary:
| Interpretation | Answer |
|---|---|
| Highest Abundance | Hydrogen |
| Highest Atomic Number (Naturally Occurring) | Uranium (and trace amounts of Plutonium) |
| Highest Atomic Number (Synthesized) | Oganesson |
Considering the typical usage of "highest," the most likely correct answer is the one related to abundance.
