Answer:
Rhodium is used to make electrical contacts, as jewelry and in catalytic converters, but is most frequently used as an alloying agent in other materials, such as platinum and palladium. These alloys are used to make such things as furnace coils, electrodes for aircraft spark plugs and laboratory crucibles.
Explanation:
D = 0.2 g / ml = 0.2 g / cm³
For example, density of steel is 7.85 g / cm³.
Density of pure water is 1.0 g/cm³. An object which has a density < 1.0 g/cm³ will float in water.
Answer: Material that has a density of 0.2 g/ml ( 0.2 g/cm³ ) is good for making couch cushions.
C. The mass number is the amount of Protons and electrons there are combined, so 200 - 80 is 120.
13) "..From the ___" My guess would be Sun since it says solar later in the question. Then an example of solar energy would be flashlights, thermostats (etc..)
14) Mechanical
16) Conductors, (Ex. copper, metal)
17) Insulators, most non metallic materials (Ex. cloth, or rubber, plastic)
18) Electrocution