Answer: 2948
Explanation:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant = 
t = age of sample = ?
a = let initial amount of the reactant = 100
a - x = amount left after decay process = 
Thus the fossil is 2948 years old.
The air in the sky and the clouds are gas, however some things in the sky [such as the sun/moon] are solid.
Hope that helped!
Answer:
The answer to your question is P = 1.64 atm
Explanation:
Data
Volume = 2.5 x 10⁷ L
Temperature = 22°C
Pressure = ?
Moles = 1.7 x 10⁶
R = 0.082 atm L/ mol°K
Process
1.- Convert temperature to °K
Temperature = 22 + 273
= 295°K
2.- Use the Ideal gas law to solve this problem
PV = nRT
- Solve for P
P = nRT / V
- Substitution
P = (1.7 x 10⁶)(0.082)(295) / 2.5 x 10⁷
- Simplification
P = 41123000 / 2.5 x 10⁷
- Result
P = 1.64 atm
Answer:
55.52°
Explanation:
Concept tested: Sine rule of triangles
We need to know the sine rule
- According to sine rule, if the three sides of a triangle are a, b and c and the corresponding angles, A, B and C
- Then,
In this case;
- If we take, a = 5.7 units and A = 70°, and
b= 5 units, B = x°
- Using the sine rule we can find the value of x
Therefore;
Then;
Therefore, X = 55.52°
Therefore, the value of x in the triangle is 55.52°
question 1
moles = mass/molar mass of Al(OH)3
convert Kg to g
that is 1.09 x 1000=1090g
moles is therefore=1090g/78(molar mass of Al(OH)3)= 13.974 moles
question 2
moles=2.55g/327.2(molar mass of Pb(CO3)2= 7.79 x 10^-3 moles
from avogadro constant
1moles=6.02 x10^23 formula units
what about 7.79 x 10 ^-3
={(7.79 x 10^-3)moles x ( 6.02 x10^23)} /1 mole=4.69 x10^21 formula units
