Answer:
Radioactive dating is a method of dating rocks and minerals using radioactive isotopes. This method is useful for igneous and metamorphic rocks, which cannot be dated by the stratigraphic correlation method used for sedimentary rocks. Over 300 naturally-occurring isotopes are known.
Number 1 is Comets and asteroids
Number 2 is Comets are made of ice and rock
Number 3 is Meteor
Answer: -
The approximate number of atoms in a bacterium is 10¹¹
Explanation: -
We are given the mass of a bacterium is 10⁻¹⁵ kg.
We are told that the mass of a hydrogen atom is 10⁻²⁷ kg.
Finally we learn that the average mass of an atom of the bacterium is ten times the mass of a hydrogen atom.
Mass of an atom of bacterium = 10 x mass of hydrogen atom
= 10 x 10⁻²⁷ kg.
= 10⁻²⁶ kg.
Thus the number of atoms in a bacterium = 
= 
= 10¹¹
Answer:
0.06819 atm or 51.8559 torr
Explanation:
To solve this problem we will use the following equation:
ln(P1/P2) = H (vap) / R (1/T2- 1/T1)
Given data:
P1= 760 torr
P2= ?
T1= 78.4 °C+273 = 351.4 K
T2= 19°C + 273 = 292 k
heat of vaporization = 38.56kJ/mol
Now we will put the values in equation:
ln (760 torr/ P2) = 38.56 × 1000 j/ 8.314 j k-1 (1/ 292 - 1/ 351.4)
ln (760 torr/ P2) = 2.6849
760 torr/ P2 = 14.656
P2 = 51.8559 torr
or
P2= 51.8559 torr × 0.001315 atm
P2 = 0.06819 atm
