They become an ionic bond, and are weakly bonded compared to covalently bonded atoms
Answer:
4.66 x 10^8 yr
Explanation:
The age of the rock can be calculated using the equation:
ln (N/N₀) = - kt where N is the quantiy of radioisotope decayed and N₀ is the initially quantity present of the radioisotope; k is the decay constant, and t is the time.
Now from the data , we have 78 argon-40 atoms for every 22 potassium-40 atoms, we can deduce that originally we had 22 + 78 = 100 atoms of potassium-40 so this is our N₀.
When we look at the equation, we see that k is unknown, but we can calculate it from the half-life which is given by the equation:
k = 0.693/ t half-life = 0.693/ 1.3 x 10⁹ yr = 5.33 x 10⁻¹⁰ yr⁻¹
Now we are in position to answer the question.
ln ( 78/100 ) = - (5.33 x 10⁻¹⁰ yr⁻¹ ) t
- 0.249 = - 5.33 x 10⁻¹⁰ yr⁻¹ t
0.249/ 5.33 x 10⁻¹⁰ yr⁻¹ = t
4.66 x 10^8 yr
Answer:
See explanation
Explanation:
i) Oxidation half-reaction:
2Ag(s) ----> 2Ag^+(aq) + 2e
Reduction half-reaction:
Ni^2+(aq) + 2e ----> Ni(s)
ii) Ag is the anode while Ni is the cathode
iii) E°cell = E°cathode - E°anode
E°cell = (-0.25) - (0.80)
E°cell = -1.05 V
iv) This is an electrolytic cell since the cell reaction is non spontaneous.
The reaction is called exothermic because an exothermic process releases heat, causing the temperature of the immediate surroundings to rise and thats exactly what charcoal does when burned.