Answer:
sorry if wrong
Explanation:
Answer:
mass of the solid is measured before measuring its volume to find the density
Flourine I guess must be the answer
Advantages
Solar energy is a clean and renewable energy source.Once a solar panel is installed, solar energy can be produced free of charge.Solar energy will last forever whereas it is estimated that the world’s oil reserves will last for 30 to 40 years.Solar energy causes no pollution.Solar cells make absolutely no noise at all. On the other hand, the giant machines utilized for pumping oil are extremely noisy and therefore very impractical.Very little maintenance is needed to keep solar cells running. There are no moving parts in a solar cell which makes it impossible to really damage them.In the long term, there can be a high return on investment due to the amount of free energy a solar panel can produce, it is estimated that the average household will see 50% of their energy coming in from solar panels.
Disadvantages
Solar panels can be expensive to install resulting in a time-lag of many years for savings on energy bills to match initial investments.Electricity generation depends entirely on a countries exposure to sunlight; this could be limited by a countries climate.Solar power stations do not match the power output of similar sized conventional power stations; they can also be very expensive to build.Solar power is used to charge batteries so that solar powered devices can be used at night. The batteries can often be large and heavy, taking up space and needing to be replaced from time to time.
Answer:
(4) concentrated and supersaturated
Explanation:
At 50.°C, 90g of KNO3 lies above the solubility curve [on the Regents Reference Table G]. This indicates that the solution is supersaturated, meaning it contains more solute than will naturally dissolve, and was formed when a saturated solution cooled. Furthermore, the percent concentration of this solution is 90% KNO3 making this solution concentrated. This can be calculated using the formula for mass percent concentration.
Percent Mass = <u>Mass of Solute (g)</u> x 100
Mass of Solution (g)