Answer:
Four moles of electrons
Explanation:
The reactions in a breathalyzer are redox reactions. Fuel cell breathalyzers consists of fuel cells with platinum electrodes. The current produced depends on the amount of alcohol in the breath. Detection of alcohol involves the oxidation of ethanol to ethanoic acid. The two half cells set in the process are;
Anode;
C2H5OH(aq) + 4OH^-(aq) ----------> CH3COOOH(aq) + 3H2O(l) + 4e
Cathode;
O2(g) + 2H2O(l) +4e--------> 4OH^-(aq)
Hence four electrons are transferred in the process.
Answer:

Explanation:
The cation contains 51 protons and 48 electrons. The electrons are only lost not protons, so the element which corresponds to atomic number 51 is the cation which is Antimony (Sb).
Also, the charge on the cation is 51 - 48 = 3
This is because neutral atom contains the same number of electrons as protons.
Given the anion has one-third protons as cation which means thta:
Number of protons in anion = 
This corresponds to chlorine atom. The electrons are 1 greater than protons means that it has gain 1 electron.
So,
Sb Cl
3 1
Cross multiply the valency.
So, formula is 
Answer:
I <em><u>THINK mechanical energy</u></em>
Oxygen is the only element in the list.
The activity of the sample is:
R₀ = 4.5 x 10⁻⁶ Ci (3.70 x 10¹⁰ decays/s / 1 Ci)
= 166500 decays / s
The number of nuclei is:
N₀ = (166500 decays/s) / (5730 yr * 3.154 x 10⁷s /1yr) = 9.2 x 10⁻⁷
The mass of a ₆C¹⁴ source is:
m = N₀m₀ = (9.2 x 10⁻⁷) * (2.34 x 10⁻²⁶) = 2.16 x 10⁻³² kg