A wave of vibrating electric and magnetic energy
Answer : The time passed in years is 
Explanation :
Half-life = 5730 years
First we have to calculate the rate constant, we use the formula :
Now we have to calculate the time passed.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant = 
t = time passed by the sample = ?
a = let initial amount of the reactant = X g
a - x = amount left after decay process = 
Now put all the given values in above equation, we get
Therefore, the time passed in years is
The amount of CaCo3 remaining is 11.5g
Answer:
See Explanation
Explanation:
In the first case, when potassium iodide is added to an aqueous bromine solution, a chemical reaction occurs as follows;
Br2(l) + 2 KI(aq) = 2 KBr(aq) + I2(l)
This reaction produces iodine solution which is brown in colour.
Secondly, when potassium iodide is added to aqueous chlorine solution, the following reaction occurs;
2KI(aq) + Cl2(l)→ 2KCl(aq) + I2 (l)
This reaction also yields iodine solution which is brown in colour.
KI(aq) + I2(l) -------->K^+(aq) + I3^-(aq)
The I3^-(aq) solution appears brown at high concentrations.
<span>Chemical change would be happening. Colorless is a physical property on its own, Determining change to requirements you have to compare two things. Is this a physical property or is this a Chemical change and color in itself would represent a change in chemical properties to the aqueous salt solutions.</span>
