Answer: The partial pressure of oxygen in the mixture if the total pressure is 525 mmHg is 310 mm Hg
Explanation:
mass of nitrogen = 37.8 g
mass of oxygen = (100-37.8) g = 62.2 g
Using the equation given by Raoult's law, we get:

= partial pressure of
= ?

= total pressure of mixture = 525 mmHg


Total moles = 1.94 + 1.35 = 3.29 moles


Thus the partial pressure of oxygen in the mixture if the total pressure is 525 mmHg is 310 mm Hg
False
Although we use many of their ideas to describe atoms today, such as the existence of a tiny, dense nucleus in an atom (proposed by Rutherford), or the notion that all atoms of an element are identical (proposed by Dalton), some of their ideas have been rejected by the modern theory of the atom.
For example, Thompson came up with the plum pudding model to describe an atom, which resembled a sphere of positive charge with electrons embedded in it. We know now, however, that atoms are mostly empty space with a tiny, dense nucleus.
Another example is Dalton's atomic theory, which stated that atoms are indivisible particles. However, this was disproved by the discovery of subatomic particles.
The age of the fossil given the present amount of Carbon-14 is given in the equation,
A(t) = A(o)(0.5)^t/h
where A(t) is the current amount, A(o) is the initial amount, t is time and h is the half-life. Substituting the known values to the equation,
A(t) / A(o) = 0.125 = (0.5)^(t/5730)
The value of t from the equation is 17190.
Thus, the age of the fossil is mostly likely to be 17190 years old.