Answer:
4121 years
Explanation:
From;
0.693/t1/2 = 2.303/t log No/N
t1/2= half life of the carbon-14
No= count rate of the living tissue
N= count rate of the sample
t = age of the sample
0.693/5730 =2.303/t log (13.5/8.2)
1.21 * 10^-4 = 2.303/t * 0.2165
1.21 * 10^-4 = 0.4986/t
t = 0.4986/1.21 * 10^-4
t = 4121 years
Vol.250 before its to much pressure
A neutral atom of potassium has 19 electrons.
Answer:
187.34 atm
Explanation:
From the question,
PV = nRT.................. Equation 1
Where P = Pressure, V = Volume, n = number of mole, R = molar gas constant, T = Temperature.
make P the subject of the equation
P = nRT/V.............. Equation 2
n = mass(m)/molar mass(m')
n = m/m'............... Equation 3
Substitute equation 3 into equation 2
P = (m/m')RT/V............ Equation 4
Given: m = 46 g, T = 25°C = (25+273) = 298 K, V = 3.00 L
Constant: m' = 2 g/mol, R = 0.082 atmL/K.mol
Substitute these values into equation 4
P = (46/2)(0.082×298)/3
P = (23×0.082×298)/3
P = 187.34 atm
Answer:
The empirical formula is PCl3
Explanation:
Mass of P is 30.97 g, thus 1.523 g of P equivalent to 0.05 moles of P
Mass of Cl is 35.45 g, thus 5.228 g of Cl equivalent to 0.15 moles of Cl
Therefore moles of P : moles of Cl = 0.05:0.15 = 1:3
Therefore the empirical formula, PCl3
