Answer:
A. because there both high pitched voice and low pitched ( girls have sweet, shrill ,high pitched good voice ) where as boys have horase ,low pitched medium voice )
The combination of seatbelts and airbags can reduce the risk of death in a collision by up to 80%.
The seatbelts help to keep the person in one position and prevent impact with the vehicle as the vehicle comes to a sudden stop. Moreover, the airbag increases the time of collision to reduce the impact experienced by the person. An increased time of collision greatly reduces the damage that is done to the body.
Find the number of moles of sodium you have:
<span>n = m/M where m is your 20g of sodium and M is 22.99 g/mol. </span>
<span>Look at the stoichiometry of the equation - it's 2:2 when you are producing NaOH. So if you took 1 mole of Na, it'd produce 1 mole of NaOH (as the ratio is equal). </span>
<span>That means that your moles of sodium is equal to the moles of NaOH produced. Use the molar mass of NaOH - which is 39.998 g/mol along with your calculated number of moles to get the mass (the formula rearranges to m = nM). </span>
<span>This figure is the theoretical yield - what you would get if every last mole of sodium was converted into NaOH. </span>
<span>What you get in practice is the experminetal yield, and the percentage yield is the experimental yield divided by the theoretical yield - and then multiplied by 100%.</span>
Before............................
<span>It is important to test only one variable when conducting an experiment because that one variable will only have one change. You want to know whether or not that one change is what caused the outcome of the experiment. If you use too many you don't know what really caused the outcome.</span>
