Is it always possible to identify something as an element compound pure substance or mixture just by looking at it

What is the correct term for living the most sustainable life you can within your current circumstances?

Identify the missing numbers below to show the result of multiplying the numbers (1.6 × 10-19)(5.0 × 106) = c × 10d

Acompound has a molecular weight of 12.124 atomic mass units and the empirical formula c3h40. what is the molecular formula of the compound?