Answer:
Light moves at 300,000 kilometers per second, divide these and you get 500 seconds, or 8 minutes and 20 seconds this is an average number.
Explanation:
Answer:
.056
Explanation:
H+=10^-pH
- Hope that helps! Please let me know if you need further explanation.
Answer:
5.0 x 10⁹ years.
Explanation:
- It is known that the decay of a radioactive isotope isotope obeys first order kinetics.
- Half-life time is the time needed for the reactants to be in its half concentration.
- If reactant has initial concentration [A₀], after half-life time its concentration will be ([A₀]/2).
- Also, it is clear that in first order decay the half-life time is independent of the initial concentration.
- The half-life of K-40 = 1.251 × 10⁹ years.
- For, first order reactions:
<em>k = ln(2)/(t1/2) = 0.693/(t1/2).</em>
Where, k is the rate constant of the reaction.
t1/2 is the half-life of the reaction.
∴ k =0.693/(t1/2) = 0.693/(1.251 × 10⁹ years) = 5.54 x 10⁻¹⁰ year⁻¹.
- Also, we have the integral law of first order reaction:
<em>kt = ln([A₀]/[A]),</em>
where, k is the rate constant of the reaction (k = 5.54 x 10⁻¹⁰ year⁻¹).
t is the time of the reaction (t = ??? year).
[A₀] is the initial concentration of (K-40) ([A₀] = 100%).
[A] is the remaining concentration of (K-40) ([A] = 6.25%).
∴ (5.54 x 10⁻¹⁰ year⁻¹)(t) = ln((100%)/( 6.25%))
∴ (5.54 x 10⁻¹⁰ year⁻¹)(t) = 2.77.
∴ t = 2.77/(5.54 x 10⁻¹⁰ year⁻¹) = 5.0 x 10⁹ years.
Potassium oxide is an ionic compound. The potassium has a charge of <span>K+</span> and oxygen has a charge of <span>O<span>2−</span></span>. We need 2 potassium ions to balance one oxide ion making the formula <span><span>K2</span>O</span>.
Potassium hydroxide is an ionic compound. The potassium has a charge of <span>K+</span> and hydroxide has a charge of <span>OH−</span>. We need 1 potassium ion to balance one hydroxide ion making the formula KOH.
<span><span>K2</span>O+<span> H2</span>O→KOH</span>
To balance the equation we place a coefficient of 2 in front of the potassium hydroxide.
<span><span>K2</span>O+<span>H2</span>O→2KOH</span>
I hope this was helpful.
Yeah...it should be out of your system by then
