According to the density of the liquid, we can get the mass of liquid is 70*0.85=59.5 g. So the total mass is 59.5+60.75=120.25 g.
Answer:
2.1x10⁹ years
Explanation:
U-238 is a radioactive substance, which decays in radioactive particles. It means that this substance will lose mass, and will form another compound, the Pb-206.
The time need for a compound loses half of its mass is called half-life, and knowing the initial mass (mi) and the final mass (m) the number of half-lives passed (n) can be found by:
m = mi/2ⁿ
The mass of Pb-206 will be the mass that was lost by U-238, so it will be mi - m. Thus, the mass ration can be expressed as:
(mi-m)/m = 0.337/1
mi - m = 0.337m
mi = 1.337m
Substituing mi in the expression of half-life:
m = 1.337m/2ⁿ
2ⁿ = 1.337m/m
2ⁿ = 1.337
ln(2ⁿ) = ln(1.337)
n*ln(2) = ln(1.337)
n = ln(1.337)/ln2
n = 0.4190
The time passed (t), or the age of the sample, is the half-life time multiplied by n:
t = 4.5x10⁹ * 0.4190
t = 1.88x10⁹ ≅ 2.1x10⁹ years
Substance A is ionic because in molten and aqueous solution conduct electricity and dissolves in water. This is because it dissociate in ions and ion conduct electicity and dissolve in polar molecules (water). Ionic bond is very strong (high melting point).
Substance B non polar covalent, because it is not dissolve in polar molecules and has weak intermolecular forces (low melting point).
Substance C is polar covalent because polar molecules have stronger intermolecular forces than non-polar and higher melting points.
False. gases have to greatest freedom of motion
