As a couple of people have pointed out, human hearing ranges from 10 Hz to 10,000 Hz, but as people get older and as they damage their hearing by listening to very loud music, firing guns without ear protection, working in very noisy environments or having other physical damage, that upper end drops off. At 64 yrs old, with a long history of a target shooter before we thought about ear protection, and after many years as a rock and roll disk jockey.<span>
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8 minutes and 25 seconds is the same as 8.25 in decimal form.
Divide by 60 minutes.
60 / 8.25 = 7.27 miles per hour
Best of Luck!
The reaction between the lead iodide, PbI2 and sodium carbonate, Na2CO3, will form the chemical compounds, sodium iodide and lead carbonate as shown below.
PbI2 + Na2CO3 --> NaI + PbCO3
The white precipitate formed in the reaction is PbCO3.
Answer:
1. Alkali metals (group 1)
2. halogens (Group 17)
3. noble gasses (group 18)
Explanation:
1. alkali metals only have one valence electron meaning that they really want to lose that one valence electron to get a full octet.
2. halogens have 7 valence electrons meaning that they just need to gain 1 to get a full octet.
3. Nobel gasses already have a full octet meaning that they don't want to react. (atoms only react to get a full octet)
I hope this helps. Let me know if anything is unclear.
