Measuring the ratio of C-14 to C-12 in the remains of dead organisms to determine how much time has passed since the organism died
the answer is D
A is correct because there is no reaction involved
Answer:
As the y-intercept increases, the graph of the line shifts up;
As the y-intercept decreases, the graph of the line shifts down
Explanation:
There are two ways to think about this problem. The first way would be the graphical approach:
- if we only change the y-intercept, this means we keep the same slope;
- y-axis is the vertical axis;
- if we change the point at which the line crosses the y-axis, we either shift it upward for a higher y-intercept or downward for a lower y-intercept.
Now, thinking algebraically, a line has the following equation in a general form:

The y-intercept is essentially obtained when x = 0, then:
y = b:
- if we increase b value, the y value increases, so the graph shifts upward;
- if we decrease b value, the y value decreases, so the graph shifts downward.
Answer:
14.4g
Explanation:
First, we need to write a balanced equation for the reaction between Fe and O2 to produce Fe2O3. This is illustrated below:
4Fe + 3O2 —> 2Fe2O3
From the balanced equation,
4moles of Fe produced 2moles of Fe2O3.
Therefore, 0.18mol of Fe will produce = (0.18x2) /4 = 0.09mol of Fe2O3.
Now we need to find the mass present in 0.09mol of Fe2O3. This can be achieved by doing the following:
Molar Mass of Fe2O3 = (56x2) + (16x3) = 112 + 48 = 160g/mol
Number of mole of Fe2O3 = 0.09mol
Number of mole = Mass /Molar Mass
Mass = number of mole x molar Mass
Mass of Fe2O3 = 0.09 x 160 = 14.4g
Answer:
Explanation:
a )
1.25 g MgO contains .754 g of Mg .Rest will be O
so oxide = 1.25 - .754 = 0.496 g
ratio of magnesium to oxide = .754/.496 = 1.52
b) 1.25 g of MgO contains .754 g of Mg
534 g of MgO contains .754 x 534 / 1.25 g = 322.11 g