Answer:
C) It will accelerate.
Explanation:
According to Newton’s second law of motion, when an object is acted on by an unbalanced force, it will accelerate.
An unbalanced force will change the speed or direction (or both) of an object. A change in speed and/or direction is acceleration.
A) is wrong. The object will stop moving only if there is a balanced force in the opposite direction.
B) is wrong. The object will decrease speed only if the unbalanced force has a component opposite to the direction of motion.
d) is wrong. The object will increase speed only if the unbalanced force has a component in the direction of motion.
Answer:
I would say the last one because mass is not created nor destroyed.
Explanation:
Period are going left to right across the periodic table
Groups are going up to down on the periodic table
Answer:
Explanation:
The usefulness of a buffer is its ability to resist changes in pH when small quantities of base or acid are added to it. This ability is the consequence of having both the conjugate base and the weak acid present in solution which will consume the added base or acid.
This capacity is lost if the ratio of the concentration of conjugate base to the concentration of weak acid differ by an order of magnitude. Since buffers having ratios differing by more will have their pH driven by either the weak acid or its conjugate base .
From the Henderson-Hasselbach equation we have that
pH = pKa + log [A⁻]/[HA]
thus
0.1 ≤ [A⁻]/[HA] ≤ 10
Therefore the log of this range is -1 to 1, and the pH will have a useful range of within +/- 1 the pKa of the buffer.
Now we are equipped to answer our question:
pH range = 3.9 +/- 1 = 2.9 through 4.9
