A. The radioactive decay equation is N = N0
where T is the
half-life (5730 years), N0 is the number of atoms at time t = 0 and
N is the number at time t.
Rewriting this as:
(N/N0) = 
Since N = (1/8) N0 and
substituting known values:
1/8 = 
Taking ln of both
sides:
ln(1/8)= -ln(2)*t/5730
t = - 5730 * ln(1/8) /
ln (2)
t = 17,190 years
The tree was cut down 17,190
years ago.
B. N0 = 1,500,000 carbon-14 atoms
Since N = (1/8) N0
N = 187,500 carbon
atoms left
An increase in the atmospheric concentrations of greenhouse gases produces a positive climate forcing, or warming effect. From 1990 to 2015, the total warming effect from greenhouse gases added by humans to the Earth's atmosphere increased by 37 percent.
Answer:
76.875 cm3
<h2>
Explanation:</h2>
Since: Density = 
Then: Volume = 
The mass of the box = 246g
and the density = 3.2 g/cm3
Then: The volume = 
= 76.875 cm3
Your general impression suggests that your immediate action should be to call for additional help. The correct option is a.
<h3>What is immediate action?</h3>
Immediate actions are the actions that are taken without taking any time. These actions are taken when there is no time to think, and you should immediately think about the actions. The emergency condition needs immediate help.
During the time of general impression, one should immediately call for additional help. Additional people will give you suggestions for the problem.
Thus, the correct option is a. call for additional help.
To learn more about immediate action, refer to the link:
brainly.com/question/28084658
#SPJ4
Answer:
Explanation:
complete combustion reaction of ethane is given by the reaction
2C2H6+7O2..............4CO2+6H2O
no of moles in 34 grams of O2=34/32=1.063
7mole of O2 produced 6 moles of H2O
therefore 1.063 moles of O2 produced=1.063*6/7=0.9 moles
now 0.9 moles of H2O contain how much grams=0.9*18=16.2 grams