Answer:
Explanation:
count given by old sample = .97 disintegrations per minute per gram
count given by fresh sample = 6.68 disintegrations per minute per gram
Half life of radioactive carbon = 5568 years
rate of disintegration
dN / dt = λ N
In other words rate of disintegration is proportional to no of radioactive atoms present . As number reduces rate also reduces .
Let initial no of radioactive be N₀ and after time t , number reduces to N
N₀ / N = 6.68 / .97
Now
λ is disintegration constant
λ = .693 / half life
= .693 / 5568
= .00012446 year⁻¹
Putting the values in the equation above
1.929577 = .00012446 t
t = 15503.6 years .
High potential for harm and abuse
Some Potassium bromide precipitates out of solution.
Option B.
<h3><u>Explanation:</u></h3>
Solubility is defined as the tendency of a substance to get mixed into a solvent at a particular temperature and pressure. The amount of solubility is defined as the amount of substance in grams which will make a saturated solution of 100ml at a temperature and pressure.
Potassium bromide is a salt and nitrogen is a gas. The solubility of the salts generally increase with temperature in water, and decreases with decrease in temperature. So in case of potassium bromide, the solubility of the salt will decrease, leaving some precipitate in the room temperature.
While in case of gases, the solubility of them do decrease with increase in temperature. So at room temperature, solubility of nitrogen will be more than that in 750°C. So no gas will bubble off.
It have to be Darwin or Mendel
hope this helps
