
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
The chemical element ruthenium (Ru) is the fourth element that exhibits unique magnetism at room temperature, apart from iron (Fe), cobalt (Co), and nickel (Ni). The atomic radius of ruthenium (Ru) is approximately $0.000000000189m$. Express $0.000000000189$ in scientific notation as ______.

Present the answer in LaTex format: \boxed{Your answer}
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