Answer:
D
Explanation:
Because speed is a scalar quantity which he has only magnitude and no direction while velocity is a vector quantity because it has both magnitude and direction.
Answer is: a) ionization energy and electronegativity.
1) The ionization energy (Ei) is the minimum amount of energy required to remove the valence electron, when element lose electrons, oxidation number of element grows (oxidation process).
Barium, potassium and arsenic are metals (easily lost valence electrons), chlorine is nonmetal (easily gain electrons).
Alkaline metals (far left in Periodic table) have lowest ionizations energy and easy remove valence electrons (one electron), earth alkaline metals (next right to alkaline metals) have higher ionization energy than alkaline metals, because they have two valence electrons.
Nonmetals are far right in the main group and they have highest ionization energy, because they have many valence electrons.
2) Electronegativity (χ) is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.
Atoms with higher electronegativity attracts more electrons towards it, electrons are closer to that atom.
Nonmetals hava higher electronegativity than metals and metalloids.
3) The atomic radius decreases across the periods because an increasing number of protons, because greater attraction between the protons and electrons.
Answer:

Explanation:
pH is derived from the concentration of hydronium ions in a solution. Hydrocyanic acid is HCN.
First, we shall figure out the moles of HCN:

If HCN was a strong acid:
HCN has a 1:1 ratio of H+ ions, the moles of H+ is also the same.
To find the molarity, we now divide by Liters. This gets us:

Finally, we plug it into the definition of pH:
![pH = -log[H^{+} ]](https://tex.z-dn.net/?f=pH%20%3D%20-log%5BH%5E%7B%2B%7D%20%5D)


However, since HCN is a weak acid, it only partially dissociates. The
of HCN is
.
![K_a = \frac{[H^+][A^-]}{[HA]}](https://tex.z-dn.net/?f=K_a%20%3D%20%5Cfrac%7B%5BH%5E%2B%5D%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
We can use an ice table to determine that when x = H+,

![[H^+] = 8.83*10^{-6}](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%20%3D%208.83%2A10%5E%7B-6%7D)
![pH = -log[H^{+} ]](https://tex.z-dn.net/?f=pH%20%3D%20-log%5BH%5E%7B%2B%7D%20%5D)


From the information in the question, the E° and E for the cell is 0.00 V and 0.12 V.
Using the Nernst equation;
Ecell = E°cell - 0.0592/n log Q
We know that E°cell = 0.00 V since the anode and cathode are both made up of cadmium.
Substituting the given values into the Nernst equation;
Ecell = 0.00 V - 0.0592/2 log (1.0 × 10-5 M/0.100 M)
Ecell = 0.00 V - 0.0296 log(1 × 10^-4)
Ecell = 0.12 V
Learn more: brainly.com/question/8646601