The answer to the question is radium (Ra)
Applications of iron oxide nanoparticles include terabit magnetic storage devices, catalysis, sensors, superparamagnetic relaxometry (SPMR), and high-sensitivity biomolecular magnetic resonance imaging (MRI) for medical diagnosis and therapeutics.
Density is a physical property. It's measured and doesn't change the object chemically.
A homogeneous mixture is uniform throughout, like water that has dissolved gases. You cannot easily distinguish the individual parts of the mixture. Many other drinks are considered homogeneous too. Laundry detergent and colognes are other examples of homogeneous mixtures. Homogeneous mixtures can also be a solid (ie. steel), liquid or gas form. It does not always have to be a liquid.