5.58 X 
Litres is the volume, in liters, occupied by 0.015 molecules of oxygen at STP.
Explanation:
Data given:
molecules of oxygen = 0.015
number of moles of oxygen =?
temperature at STP = 273 K
Pressure at STP = 1 atm
volume = ?
R (gas constant) = 0.08201 L atm/mole K
to convert molecules to moles,
number of moles = 
number of moles = 2.49 x 
Applying the ideal gas law since the oxygen is at STP,
PV = nRT
rearranging the equation:
V = 
putting the values in the rearranged equation:
V = 
V = 5.58 X Litres.
Three of them may have decayed more quickly or more slowly than they should have according to the likelihood at that particular moment. However, suppose we have a lot of radioactive new Clyde's, say six times 10 to the 12, and we have three times 10 to the 12 in a minute. The rate may then be averaged out because there are a sufficient number of radioactive new Clyde's. Furthermore, we can say with confidence that the half life is one minute.
<h3>What is radioactivity?</h3>
Radioactivity, as its name suggests, is the act of generating radiation without any external cause. An atomic nucleus that is unstable for whatever reason does this by "wanting" to give up some energy in order to change its configuration to one that is more stable. Modern physics spent a lot of time in the first half of the 20th century figuring out why this occurs, which led to a pretty solid understanding of nuclear decay by 1960. A nucleus with too many neutrons will produce a negative beta particle, which will convert one of the neutrons into a proton. A nucleus with too many protons will emit positrons, which are positively charged electrons that turn protons into neutrons.
To know more about radioactivity:
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Answer:Artificial light from cities has created a permanent "skyglow" at night, obscuring our view of the stars. Here's their map of artificial sky brightness in North America, represented as a ratio of "natural" nighttime sky brightness. In the black areas, the natural night sky is still (mostly) visible.
Explanation:
17.8 mL NaOH
<em>Step 1.</em> Write the chemical equation
Fe^(2+) + 2NaOH → Fe(OH)2 + 2Na^(+)
<em>Step 2.</em> Calculate the moles of Fe^(2+)
Moles of Fe^(2+) = 500 mL Fe^(2+) × [0.0230 mmol Fe^(2+)]/[1 mL Fe^(2+)]
= 11.50 mmol Fe^(2+)
<em>Step 3.</em> Calculate the moles of NaOH
Moles of NaOH = 11.50 mmol Fe^(2+) × [2 mmol NaOH]/[1 mmol Fe^(2+)]
= 23.00 mmol NaOH
<em>Step 4.</em> Calculate the volume of NaOH
Volume of NaOH = 23.00 mmol NaOH × (1 mL NaOH/1.29 mmol NaOH)
= 17.8 mL NaOH
