What is the difference between mass and volume? [explaine before i give brainliest]

One similarity and one difference between an element and a mixture of elements

When hydrogen peroxide (h2o2) is added to potassium iodide (ki) solution, the hydrogen peroxide decomposes into water (h2o) and oxygen (o2). the chemical equation for the decomposition reaction is: 2h2o2—> 2h2o + o2. what is the role of the potassium iodide in this reaction? a. reactant. b. product. c. precipitate. d. catalyst.

Why sncl2 is solid while sncl4 is liquid at room temprature explain it in easy way