To calculate atomic mass, you have to take to weighted average of the isotopes' masses. What that means is M = RA*106 + (1 – RA)*104, where RA is relative abundance expressed in decimal form. If you simplify the right side of that equation, you get M = 2*RA + 104. Doing a little more algebra yields RA = (M –104)/2 = (104.4 – 104)/2 = 0.4 / 2 = 0.2, which is 20%. So the answer is B.
Answer: So let's say you climbed on top of a tree in your backyard and decided you wanted to drop some acorns down at people. We will assume there is no air resistance (we live in some vacuum world) and remembering that the total mechanical energy of the system is constant
A. Ammonium = polyatomic ion
B. Oxygen = compound
C. Silver = element
D. Nitrate = polyatomic ion
E. Helium = element
F. Water = polyatomic ion
G. Nitrogen = element
H. Carbon dioxide = compound
Answer:
Q9. The independent variable in this experiment is the fertilizer. It is independent because she manipulating the variable to compare the growth.
Q10. The dependent variable in this experiment is the amount of growth of the corn. It is this because the growth depends on what the scientist did on the corn.
Q11. The variable controlled in this experiment is the amount of sun and water. These two variables never change so this is why it is the control.
Explanation: