Answer:
37S
Explanation:
Radioactivity is the spontaneous emission of particles and / or electromagnetic radiation by unstable atomic nuclei leading to their disintegration.
We have two main types of radioactivity: radioactive decay and artificial transmutation.
In radioactive decay ( natural radioactivity ), a naturally occurring radioactive element like Uranium-238 disintegrates or decays into more stable isotopes with the emission of particles and/or radiation.
23892U = 23490Th + 42He
Artificial transmutation is the collision of two particles where one particle captures the other used to bombard it. There is subsequent production of isotopes similar or different from the bombarded particle. Neutrons, alpha particles ( helium nucleus ), electrons, protons can be used to bombard elements.
147N + 42He = 178O + 11P
For the above question which is artificial transmutation, the reaction equation is
4018Ar + 10n = 3716S + 42He
So, the neutron capture by Argon-40 will produce a radioisotope Sulphur-37 with the emission of an alpha particle.
Answer:
The primary type of energy change which occurs by turning on the phone will be the conversion of the stored chemical energy of the battery into electrical energy. The chemical energy is also converted into light energy, sound energy and heat energy. With the passage of time, the energy will be changed back into the chemical energy when we will charge the phone again.
<h3><u>Answer;</u></h3>
Step 1; NaHCO3(s) + CH3COOH(l)
Step 2 ; CO2(g)
<h3><u>Explanation;</u></h3>
- The chemical equation for the reaction of baking soda (sodium bicarbonate, NaHCO3) and vinegar (acetic acid, CH3COOH) reaction occurs in two steps.
Step 1;
- A double displacement reaction in which acetic acid in the vinegar reacts with sodium bicarbonate to form sodium acetate and carbonic acid:
- Equation;
NaHCO3(s)+ CH3COOH(l) → CH3COONa(aq) + H2CO3(l)
Step 2;
- Carbonic acid is unstable and undergoes a decomposition reaction to produce the carbon dioxide gas:
H2CO3(l) → H2O(l) + CO2(g)
C. Aluminum (Al) oxidized, zinc (Zn) reduced
<h3>Further explanation</h3>
Given
Metals that undergo oxidation and reduction
Required
A galvanic cell
Solution
The condition for voltaic cells is that they can react spontaneously, indicated by a positive cell potential.
or:
E ° cell = E ° reduction-E ° oxidation
For the reaction to occur spontaneously (so that it E cell is positive), the E° anode must be less than the E°cathode
If we look at the voltaic series:
<em>Li-K-Ba-Ca-Na-Mg-Al-Mn- (H2O) -Zn-Cr-Fe-Cd-Co-Ni-Sn-Pb- (H) -Cu-Hg-Ag-Pt-Au </em>
The standard potential value(E°) from left to right in the voltaic series will be greater, so that the metal undergoing an oxidation reaction (acting as an anode) must be located to the left of the reduced metal (as a cathode)
<em />
From the available answer choices, oxidized Al (anode) and reduced Zn (cathode) are voltaic/galvanic cells.
Answer:
∆H° rxn = - 93 kJ
Explanation:
Recall that a change in standard in enthalpy, ∆H°, can be calculated from the inventory of the energies, H, of the bonds broken minus bonds formed (H according to Hess Law.
We need to find in an appropiate reference table the bond energies for all the species in the reactions and then compute the result.
N₂ (g) + 3H₂ (g) ⇒ 2NH₃ (g)
1 N≡N = 1(945 kJ/mol) 3 H-H = 3 (432 kJ/mol) 6 N-H = 6 ( 389 kJ/mol)
∆H° rxn = ∑ H bonds broken - ∑ H bonds formed
∆H° rxn = [ 1(945 kJ) + 3 (432 kJ) ] - [ 6 (389 k J]
∆H° rxn = 2,241 kJ -2334 kJ = -93 kJ
be careful when reading values from the reference table since you will find listed N-N bond energy (single bond), but we have instead a triple bond, N≡N, we have to use this one .
