Answer: 27 neutrons
Explanation:
Recall that the number of protons in the nucleus of an atom = Atomic number.
Hence, Calcium with mass number 47 and atomic number 20 will have 20 protons
Therefore, since Mass number = number of protons + neutrons
47 = 20 + neutrons
Neutrons = 47 - 20 = 27
Thus, there are 27 neutrons in radioactive calcium nucleus.
Answer:
c. 298 K
Explanation:
Nernst equation is an equation used in electrochemistry that relates the reduction potential of a reaction with the standard potential, temperature and concentrations of the reactants in that are been reducted and oxidized. The formula is:
E = E° - RT / nF ln [Red] / [Ox]
<em>Where R is gas constant (8.314J/molK), T is absolute temperature (In Kelvin), n are moles of electrons and F is faraday constant (K/Volt*mol)</em>
<em />
In electrochemistry, standard temperature is taken as 298K. That means by assuming standard temperature we can substitute T as:
<h3>c. 298 K</h3>
Answer:
NH4+
Explanation:
NH4+ is the acid and NH3 is the base, so NH4+ is the stronger acid.
Solution:- Hypochlorite ion
has one Cl and one O atom. Cl has 7 valence electrons and O has 6 valence electrons. Since there is one negative charge on the ion,
total valence electrons = 7 + 6 +1 = 14
(note:- if there is negative charge then it is added and if there is positive charge then it is subtracted while calculating the valence electrons)
Both Cl and O atoms wants to complete their octet and so for this we put a single bond between them. Single bond means two electrons, so the remaining electrons would be 14 - 2 = 12
It means 12 electrons will be placed as lone pair of electrons. To complete the octet, we put 6 dots around each of the atom. Oxygen is more electron negative than Cl, so we show the -1 charge for oxygen.