Answer: The mass is 980.6g of Gold.
Explanation:
We begin by looking for the number of moles equivalent to 3.0 x 10^24 gold atoms.
Using the Avogadro's number,
6.02 x 10^23 atoms of gold make up 1 mole of gold.
3.0 x 10^24 atoms would make up: 1 / 6.02 x 10^23 x 3.0 x 10^24 = 4.98moles.
Now that we know the number of moles, we can then look for the mass using the formular:
Moles = mass/ molar mass
4.98 = mass / 196.9 (atomic mass of gold)
Making "mass" the subject of formula : mass = 4.98 x 196.9= 980.6g
1) 2700 kg/l
2) 13.6 kg/l
3) 0.1578 kg
4) 8921.5 kg/m3
5) 1.59 kg/l
6) 1.84 kg/l
7) 0.21965 kg
8) 11331.9 kg/m3
9) 7.9167 kg/l
10) 238.095 cm3
Just divide the masses by volume to find out the density, multiply the volume with density to find out the mass and divide the mass by density to find out the volume.
To turn the result into SI unit (kg/l), divide the g by 1000 and ml by 1000.
Astronomers can measure it by way of luminosity which is the power of a star or the amount of energy (light) the star admits from its surface. they also measure the brightness of a start as if it were to appear 32.6 light years from Earth
Answer:
11552.45 years
Explanation:
Given that:
Half life = 5730 years
Where, k is rate constant
So,
The rate constant, k = 0.00012 years⁻¹
Using integrated rate law for first order kinetics as:
![[A_t]=[A_0]e^{-kt}](https://tex.z-dn.net/?f=%5BA_t%5D%3D%5BA_0%5De%5E%7B-kt%7D)
Where,
![[A_t]](https://tex.z-dn.net/?f=%5BA_t%5D)
is the concentration at time t
![[A_0]](https://tex.z-dn.net/?f=%5BA_0%5D)
is the initial concentration
Given that:
The rate constant, k = 0.00012 years⁻¹
Initial concentration = 160.0 counts/min
Final concentration = 40.0 counts/min
Time = ?
Applying in the above equation, we get that:-
