Check every element at both sides
Element left side right side conclusion
Fe 2 1 not balanced
O 3+3=6 3*2=6 balanced
C 3 3 balanced
Answer: only Fe is unbalanced (2 atoms at the left side and 1 atom at the right side)
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
The arrow that are drawn correctly are the cool air current and the upper air current. In the sea breeze, warm air moves up because it is less dense that the cool air. The cool air moves down to replace the warm air. The land breeze current moves from the land to the sea while the sea breeze moves from the sea to the land. This creates a continuous flow of current at the sea level.
A heterozygous is represented by 1 capital letter and 1 lowercase in most instances.
Answer:
To calculate the average atomic mass, multiply the fraction by the mass number for each isotope, then add them together.
