Answer:
Option D. fluorine-18
Explanation:
The attached photo gives the explanation.
In the attached photo, A zX represent the atom that will undergo beta decay to produce oxygen–18.
After the calculation, A zX was found to be fluorine–18.
To take the percent by mass of this element, we use the
formula:
% mass = (mass of element / mass of ore) * 100%
% mass = (47.5 g / (660 kg * 1000 g / kg)) * 100*
<span>% mass = 7.20 x 10^-3 %</span>
Answer:
Forces acting on an object may be balanced or unbalanced. When the forces acting on an object have <u>equal</u> strength and act in opposite directions, they are <u>balanced</u>. These forces cancel out one another, and the <u>motion</u> of the object does not <u>change</u>. When the forces acting on an object are <u>unbalanced</u>, they do not cancel out one another. An unbalanced force acting on an object results in the object’s motion <u>changing</u>. The object may change its <u>speed</u> (speed up or slow
down), or it may change its <u>direction</u>. <u>Friction</u> is a force that resists the motion or the tendency toward motion between two objects in contact with each other. <u>Gravity</u> is a force that pulls objects toward one another. For example, Earth pulls all objects toward it.
Explanation:
13. D
14. A
15. C
16. B
17. F
18. E
